I have read so many questions and answers on this but none of them seem to fix my problem. Basically I have an HTML and CSS slideshow and I am trying to center this slideshow. I have position: absolute in the code, however when I try to remove that, the images are no longer in a slideshow and are just all down the page.   Here is my code:  &lt;body&gt; &lt;div class="container"&gt;     &lt;img src=&gt;     &lt;img src=&gt;     &lt;img src=&gt;     &lt;img src=&gt;     &lt;img src=&gt;     &lt;img src=&gt;     &lt;img src=&gt;     &lt;img src=&gt; &lt;/div&gt;  &lt;style&gt;  .container {     position:relative; } .container img {     position:absolute;     width:900px;     height:500px } @-webkit-keyframes xfade {     0% {         opacity: 1;     }     12.5% {         opacity:1;     }     16.5% {         opacity:0;     }     96% {         opacity:0;     }     100% {         opacity:1;     } } @keyframes xfade {     0% {         opacity: 1;     }     12.5% {         opacity:1;     }     16.5% {         opacity:0;     }     96% {         opacity:0;     }     100% {         opacity:1;     } } .container img:nth-child(8) {     -webkit-animation: xfade 120s 0s infinite;     animation: xfade 120s 0s infinite; } .container img:nth-child(7) {     -webkit-animation: xfade 120s 15s infinite;     animation: xfade 120s 15s infinite; } .container img:nth-child(6) {     -webkit-animation: xfade 120s 30s infinite;     animation: xfade 120s 30s infinite; } .container img:nth-child(5) {     -webkit-animation: xfade 120s 45s infinite;     animation: xfade 120s 45s infinite; } .container img:nth-child(4) {     -webkit-animation: xfade 120s 60s infinite;     animation: xfade 120s 60s infinite; } .container img:nth-child(3) {     -webkit-animation: xfade 120s 75s infinite;     animation: xfade 120s 75s infinite; } .container img:nth-child(2) {     -webkit-animation: xfade 120s 90s infinite;     animation: xfade 120s 90s infinite; } .container img:nth-child(1) {     -webkit-animation: xfade 120s 105s infinite;     animation: xfade 120s 105s infinite; }  .container {     margin: 0 auto; }  &lt;/style&gt;
How can I horizontally center a &lt;div&gt; within another &lt;div&gt; using CSS? &lt;div id=&quot;outer&quot;&gt;   &lt;div id=&quot;inner&quot;&gt;Foo foo&lt;/div&gt; &lt;/div&gt;
What is the most efficient way given to raise an integer to the power of another integer in C?  // 2^3 pow(2,3) == 8  // 5^5 pow(5,5) == 3125 Check for missing fonts/characters in XeLaTeX? How to cut a mesh by specifying the angle This is a question to experienced people that might help us shed some light on the issue.   We noticed a very strange behavior on our site, in Google Analytics. Some dude from Finland, namely, from Kouvola city is hitting one of our pages - only one page on our site, 'bout a hundred times per day, all with an average bounce rate of 90%+...  This is causing our overall bounce rate to go up by 1 to 3% per day... which is very disturbing.. since we're trying to do our best in order to keep it as low as possible. And obviously having it jumped from ~24% to 27%, just because of that crazy dude is not making us happy at all... We tried implementing a geo-targeted script in order to catch this particular visitor and deliver him a juicy message, and it seemed like it helped in the beginning, it has stopped for a day or two, but now he's back...   The geo-targeted script was also logging all IP addresses for page requests originating from Finland in order to find out more details and (in order to block them on the server level, later).. but thing is, it was all mainly cable or DSL connections with various, but not constantly repeating IPs... we are all wondering what is he up to really ?   I think that this page should be kept updated with ideas on how to combat this and perhaps someone could also shed light on what it might be ? What is the reason for doing this "bounce-rate attack", as I call it?  There was a similar question asked on stackoverflow earlier, with no meaningful answer - here - "System" storage on macOS Sierra is 470GB! Bash while read loop breaking early jQuery - setting the selected value of a select control via its text description I have a select control, and in a javascript variable I have a text string.  Using jQuery I want to set the selected element of the select control to be the item with the text description I have (as opposed to the value, which I don't have).  I know setting it by value is pretty trivial. e.g.  $("#my-select").val(myVal);   But I'm a bit stumped on doing it via the text description. I guess there must be a way of getting the value out from the text description, but my brain is too Friday afternoon-ed to be able to work it out. apt-get update fails to fetch files, “Temporary failure resolving …” error Err http://archive.canonical.com natty InRelease     Err http://security.ubuntu.com oneiric-security InRelease                Err http://extras.ubuntu.com natty InRelease                             Err http://security.ubuntu.com oneiric-security Release.gpg   Temporary failure resolving ‘security.ubuntu.com’ Err http://archive.canonical.com natty Release.gpg   Temporary failure resolving ‘archive.canonical.com’ Err http://extras.ubuntu.com natty Release.gpg   Temporary failure resolving ‘extras.ubuntu.com’ Err http://gb.archive.ubuntu.com oneiric InRelease Err http://gb.archive.ubuntu.com oneiric-updates InRelease Err http://gb.archive.ubuntu.com natty-backports InRelease Err http://gb.archive.ubuntu.com oneiric Release.gpg   Temporary failure resolving ‘gb.archive.ubuntu.com’ Err http://gb.archive.ubuntu.com oneiric-updates Release.gpg   Temporary failure resolving ‘gb.archive.ubuntu.com’ Err http://gb.archive.ubuntu.com natty-backports Release.gpg   Temporary failure resolving ‘gb.archive.ubuntu.com’  Reading package lists... Done W: Failed to fetch http://gb.archive.ubuntu.com/ubuntu/dists/oneiric/InRelease       W: Failed to fetch http://gb.archive.ubuntu.com/ubuntu/dists/oneiric-updates/InRelease   W: Failed to fetch http://gb.archive.ubuntu.com/ubuntu/dists/natty-backports/InRelease   W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/oneiric-security/InRelease   W: Failed to fetch http://archive.canonical.com/ubuntu/dists/natty/InRelease   W: Failed to fetch http://extras.ubuntu.com/ubuntu/dists/natty/InRelease   W: Failed to fetch http://archive.canonical.com/ubuntu/dists/natty/Release.gpg  Temporary failure resolving ‘archive.canonical.com’ W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/oneiric-security/Release.gpg  Temporary failure resolving ‘security.ubuntu.com’ W: Failed to fetch http://extras.ubuntu.com/ubuntu/dists/natty/Release.gpg  Temporary failure resolving ‘extras.ubuntu.com’ W: Failed to fetch http://gb.archive.ubuntu.com/ubuntu/dists/oneiric/Release.gpg  Temporary failure resolving ‘gb.archive.ubuntu.com’ W: Failed to fetch http://gb.archive.ubuntu.com/ubuntu/dists/oneiric-updates/Release.gpg  Temporary failure resolving ‘gb.archive.ubuntu.com’ W: Failed to fetch http://gb.archive.ubuntu.com/ubuntu/dists/natty-backports/Release.gpg  Temporary failure resolving ‘gb.archive.ubuntu.com’ W: Some index files failed to download. They have been ignored, or old ones used instead.   This is what I'm seeing when I try to run sudo apt-get update. I did an update on my instance yesterday and am now experiencing this. Possible Duplicate:          Sounds like a silly question, but bear with me..  If you go into Peet's Coffee and access the wifi, you're taken to a web page that requires a 4-digit code you get with a purchase.   If you do the same at Starbucks you're taken to a page and asked to OK the terms of service.   I want to build something similar for a local independent coffee shop, something that requires the user to write a little about themselves before they can access the Internet.  I'm not sure which way to go -- looking for wifi routers that run an internal web server, or finding one that lets you direct users to an external website for authentication, somehow redirecting back to the access point once successful.   Has anyone done anything like this and can share their experience? Reference sObject Fields dynamically from a string value Is it possible to reference the fields of an sObject (opportunity in this example) dynamically from a string value? For example, take the following code:  for(Opportunity o: oppList) {       for(String s : strList) {            // I'd like to set the opportunity field values based on the string             // value that contains the API name of the opportunity field       }  }  So, the variable strList contains the opportunity API field names. I'm trying to clear some fields on the opportunity in a before update trigger, but I have to access the field names dynamically in the strList. Do Indian passport holders with UK Tier 2 need to get a tourist visa for Mexico? I'm an Indian passport holder currently resident in the UK under a Tier 2 (General) visa and planning on going to Mexico on a holiday. So I was looking into the rules on the Mexican embassy in the UK and :     According to the new regulations who entered into effect on 18th, May   2016 (article 26 of the Guidelines and Requirements for Migratory   Services) regarding foreign nationals visiting Mexico, holders of a   valid UK visa, regardless their nationality, are not required to apply   for a Mexican visa as a tourist, business (Non-Lucrative Activities)   or transit visitors for a stay of up to 6 months. This regulation does   not apply to British Travel Document holders.   However, :     PERMANENT RESIDENT IN THE UK (ILR / ILE / PERMANENT RESIDENTS)        According to Mexican regulations which came into force in June 2009,   Permanent residents in the United Kingdom wishing to travel to Mexico   do not require a visa to enter the country as tourists or business   visitors for up to 180 days and as visitors in transit for up to 30   days, regardless their nationality.   So which one is correct? Are Tier 2 holders with an Indian passport allowed visa-free / visa on-arrival entry to Mexico? iCloud Disassociation for a Mac Computer I had a Mid-2012 MacBook Pro that recently stopped booting. I narrowed this down based on troubleshooting of the boot device to likely the SATA/hard drive connector/cable no longer working for whatever reason.  I have decided to sell the system. I'd like to know if I remove the hard drive (or in this case, an after-market SSD I've installed) from the system, will there be any other data (i.e. iCloud data) stored on the system on any other chip that I can reset in any way? I plan to reset the SMC/NVRAM before I sell the system off of to someone else.  Additionally, if I remove the hard drive, is the system still associated to iCloud (specifically Find My Mac) or any other service? If so, how do I disassociate it? The system will no longer boot even if I put in my boot device.  Thanks! Is the following just a matter of showing the 3 properties that make up a metric??  Define d on $\Bbb R\times\Bbb R$ by $d(x,y)=\min \{1,|x-y|\}$. Show that $d$ is a metric on $\Bbb R$     $d(x,y)=0$ if $x=y$   $d(x,y)=d(y,x)$ for every $x,y \in X$   $d(x,y)\le d(x,z)+d(z,y)$ for every $x,y,z \in X$ Show that the set of all finite subsets of $\mathbb{N}$ is countable. Show that the set of all finite subsets of $\mathbb{N}$ is countable.   I'm not sure how to do this problem. I keep trying to think of an explicit formula for 1-1 correspondence like adding all the elements in each subset and sending that sum to itself in the natural numbers, but that wouldn't be 1-1 because, for example, the set {1,2,3} would send to 6 and so would the set {2,4}.  Multiplying all the elements in each subset and sending that product to itself in the natural numbers wouldn't work either since, for example, {2,3} would send to 5 and so would the set {1,5}. Any ideas? Tighten rope without turnbuckles? I have two 4-ft x 4" x 4" wood posts, and each post has a screw eye. There's 12 feet of distance between each post.  How can I tighten a piece of 1/2" diameter rope that goes through each screw eye and it's stretched tightly without having to buy turnbuckles?  There has to be a knot just for this. Setting up SFTP to log in to server with Filezilla I have an ec2 instance on AWS which already installed a few Wordpress-es in it.  I want to set things up to let more people handle their own projects, with me also being able to go into the server using terminal if I still want to.  I have been following tutorials such as  and a few others.  I figured all of them just teach users how to sftp into their own home folder, also the steps keep saying addUser but some users already existed and removing them might cause some issue.  How can I give existing users the permission to use SFTP for Wordpress projects?  Let's say all my Wordpress projects are already under /var/www/ which has already been set up with www-data:www-data.  Really new with setting things like this.  Thanks in advance for any help. How are qubits better than classical bit if they collapse to a classical state after measurement? Classical computers store information in bits, which can either be $0$ or $1$, but, in a quantum computer, the qubit can store $0$, $1$ or a state that is the superposition of these two states. Now, when we make a "measurement" (to determine the state of qubit), it changes the state of the qubit, collapsing it from its superposition of $0$ and $1$ to the specific state consistent with the measurement result.  If from a measurement of a qubit we obtain only a single bit of information ($0$ or $1$, because the qubit collapses to either of the states), then, how is a qubit better than a classical bit? Since ultimately we are only able to get either $0$ or $1$ from either classical or quantum bit.  If you can explain with an example, it may be helpful. Game resource timers - general implementation I'm interested in understanding how resource generation timers work on many of the mmorts type games out there. I can't wrap my head exactly around how the timers are synched with servers, especially with multiple users. If I need to provide more details, please let me know.  Thanks! What does "65" mean? Problem. Assume that $U$ is an open and connected subset of $\mathbb R^2$, and $\gamma :[0,1]\to U$ is a closed curve, which is not null-homotopic in $U$ and not necessarily simple closed. Show that there exists a simple closed curve, which is not null-homotopic in $U$.  I am sure that this is a standard problem, and I am looking for an elegant, if possible, solution or a reference. I have in mind the following sketch of proof:  a. Construct a polygonal closed curve $\tilde\gamma$ which is homotopic with $\gamma$ in $U$.  b. Construct $\tilde\gamma$ so that it intersects itself in finitely many points, and not whole segments.  c. Use induction on the number of self–intersections of $\tilde\gamma$, in order to show that $\tilde\gamma$ is written as a product (in the fundamental group's sense) of simple closed polygonal curves.