I am trying to validate an email address when the submit email button is pressed.  I tried adding JQuery validation to no avail. I was wondering how I could add an "if" statement that will just check and inform the user, that it is not a valid email in the same label that states it is sending an email.    $('#Submit').on("click", function () {   result = '&lt;label style="color:white;"&gt;Sending message ...&lt;/label&gt;';   $("#sendSuccess").html(result);    var email = $("#email").val();    var body = "From: " + name + "&lt;br /&gt;  Email: " + email + "&lt;br /&gt; Message: " + message;    $.ajax({     type: "POST",     contentType: "application/json; charset=utf-8",     url: "EmailService.asmx/SendMail",     data: '{ body: "' + body + '", subject: "' + subject + '"}',     dataType: "json",     async: true,      success: function (data, status, xhr) {       //alert('success');       result = '&lt;label style="color:green;"&gt;The message has been sent!&lt;/label&gt;';       $("#sendSuccess").html(result);     },     error: function (data, status, xhr) {       //alert('fail');       result = '&lt;label style="color:red;"&gt;The message has failed to send!&lt;/label&gt;';       $("#sendSuccess").html(result);     }   }); }); &lt;script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"&gt;&lt;/script&gt; &lt;html&gt;   &lt;div&gt;     &lt;input id="email" type="text" name="email"  class="form-control" /&gt;   &lt;/div&gt;   &lt;div&gt;     &lt;button type="submit" id="Submit" class="form-control"&gt;Click&lt;/button&gt;       &lt;/div&gt;     &lt;/html&gt;
Is there a regular expression to validate an email address in JavaScript?
How to use GROUP BY to concatenate strings in SQL Server? How do I get:  id       Name       Value 1          A          4 1          B          8 2          C          9   to  id          Column 1          A:4, B:8 2          C:9 math fallacy problem: $-1= (-1)^3 = (-1)^{6/2} = \sqrt{(-1)^6}= 1$? During my attempt to upgrade my Xubuntu 14.04 installation with  sudo apt-get dist-upgrade   I made the mistake of interrupting the process by closing my laptop, which caused it to suspend to disk. After re-opening, the monitor remained black, so I was forced to reboot the system. I have since discovered many failures of drivers (wlan0 missing, USB memory stick cannot be mounted, USB mouse not recognised, and maybe more undiscovered problems with hardware).   My beginner's attempts to manually repair the single problems could have made it even worse. During the installation of the current distribution I chose to encrypt my whole hard disk. I have brand new machine.  I want to install Ubuntu and one more Linux distributions on same machine. When the machine is up I want to have the option to choose which Linux to load.   Is it possible?  How to do it? Past Subjunctive vs Future Subjunctive form Traverse a list in reverse order in Python So I can start from len(collection) and end in collection[0].  I also want to be able to access the loop index. I was having a time getting my bootable USB 3, 32GB W10 install USB to be recognized. It recognized one time but I had to restart for something and it never came up again. I eventually removed all other boot up options to make it easier and faster to try again (no F12 needed).  Finally I gave up and tried another drive (16GB this time FWIW) and then it worked.  HOWEVER, it's stuck on a reboot loop now. I can choose to install, then to select the right disk, then it says it's loading file and then next thing I know it's saying do you want to install or upgrade. When it's OK to omit "where?" I gave Google my phone number to verify it, not knowing that it would change it, and now my phone number is completely different? What have I done, and how do I unverify it and change my phone number back? How to typeset some text including math content in sans serif How to sort a list of objects based on an attribute of the objects? I've got a list of Python objects that I'd like to sort by an attribute of the objects themselves.  The list looks like:  &gt;&gt;&gt; ut [&lt;Tag: 128&gt;, &lt;Tag: 2008&gt;, &lt;Tag: &lt;&gt;, &lt;Tag: actionscript&gt;, &lt;Tag: addresses&gt;,  &lt;Tag: aes&gt;, &lt;Tag: ajax&gt; ...]   Each object has a count:  &gt;&gt;&gt; ut[1].count 1L   I need to sort the list by number of counts descending.  I've seen several methods for this, but I'm looking for best practice in Python. Let $G$ be a group, possibly a singleton. Let $M$ be a set, possibly empty. Let $\mu: M \times G \to M$ be a right group action. Let $1_G$ be the identity of $G$.  I understand 's second definition of faithful as follows:     $\mu$ is faithful if for each $g \in G$ such that $g \ne 1_G$, there exists $x \in M$ such that $\mu(x,g) \ne x$. $\tag{1}$   Later  says if $\mu$ is free and $M$ is a non-empty set, then $\mu$ is faithful.  Question: Given the idea that we can have $M$ as an empty set, I would like to clarify: Are these correct?   If $G$ is a singleton, then every action $\mu$ is faithful, whether or not $M$ is empty. If $G$ is not a singleton, but $M$ is empty, then every action $\mu$ is not faithful. Minimal $ab$ for Rational Number $a/b$ in an Interval Given rational numbers $L$ and $U$, $0&lt;L&lt;U&lt;1$, find rational number $M=a/b$ such that $L \le M&lt;U$ and $(a\times b)$ is as small as possible---$a$ and $b$ are integers. For example,    If $L=66/101$ and $U=19/29$ then $M=17/26$. If $L=66/101$ and $U=19/28$ then $M=2/3$.   Right now I'm using a naive search that is exponential in complexity. Is there a better method?  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Already awarded bounty refunded on question migration? In March 2011 I offered a 500 bounty on one of my StackOverflow questions () and awarded it to Filip de Vos.   This question was later migrated to Database Administrators and has the following messages on it.     migrated to dba.stackexchange.com by Will♦ Dec 28 '11 at 12:25      This   question belongs on our site for database professionals who wish to   improve their database skills and learn from others in the community.   .     deleted Dec 31 '11 at 1:01   I appear to have been   on whereas Filip .  Is this a bug? Definitely doesn't seem fair or correct to me. The question still shows up in both our bounty tabs despite the migration. I would have hoped that the previously awarded bounty reputation points could still be honoured in this situation. In many courses, say Linear Algebra, Group Theory, Topology, instructors often say that knowing that certaing objects are isomorphic, sometimes makes life easier because we can work with more friendly objects.  Is there any example of using isomorphism concept to solve a non trivial concrete problem?   I must say, I'm not looking on important or famous isomorphic objects, but on non trivial application of the concept of isomorphism used in order to solve another kind of problem.