Regular Expression for characters but number and space optional using asp.net web forms.  These are acceptable strings:   Mazhar  mazhar123  mazhar khan1   These are not acceptable:  1233444 @@@@@@ Mazhar@kkk   All Special characters should not be acceptable as well.
I don't really understand regular expressions.  Can you explain them to me in an easy-to-follow manner?  If there are any online tools or books, could you also link to them?
How do you effectively study physics? How does one read a physics book instead or just staring at it for hours?   (Apologies in advance if the question is ill-posed or too subjective in its current form to meet the requirements of the FAQ; I'd certainly appreciate any suggestions for its modification if need be.) Bind a key for multiple units to use the same spell Is there a way for me to bind a key that will allow multiple units in my control group to all use the same spell at once?  For example, if I have 3 centaurs as chen, and I have them all selected. Can I press one key to make them all warstomp at the same time?   Or if I have 3 familiars as Visage. When I have all three selected, is there a button I can press to have them all stun at the same time? How can I immediately detect when new files added to a folder within a  script? I would like the script to process files as soon as they are created in the folder. Are there any methods aside from scheduling a  job that checks for new files each minute or so? Too big of a sofa Do spell effects move if the object they are cast on moves? let's suppose that I cast a Silent image of a wall on an airship. Let's suppose that I don't move it with concentration.  Does the image of the wall move with the airship or it will progressively go far? What does "may they rot there" mean? Getting a System.Type from type's partial name I want to get a System.Type given only the type name in a string.  For instance, if I have an object:  MyClass abc = new MyClass();   I can then say:  System.Type type = abc.GetType();   But what if all I have is:  string className = "MyClass"; Optimization paramters read-only mysql 5.7 database? What's the best way to configure a MySQL database that is only read-only, and will never have any modifications made to it?  1) I have increased my innodb_buffer_pool_size to 70% of available RAM  2) Increase query cache size to 40mb  Running against a load generator, after some time the database starts bottlenecking to only 1000 statements per second.  The configuration is 2-cores, 8GB ram 50GB SSD. The database contains a single InnoDB 13 GB table with the same exact query running on two indexed columns.  We are using a vertx server to hit the database. The symptom we see is that the web service performance degrades after 15-20 minutes of heavy load.  Where can the bottleneck be? What parameters should we optimize? WordPress Installation Failed I am trying to install Wordpress on Lubuntu. I followed the instructions . Including PHP Apache and MySQL setups. Apache and MySQL appear to be running fine.  However, when I go to http://localhost/blog/, I get the following error:     Neither /etc/wordpress/config-localhost.php nor /etc/wordpress/config-localhost.php could be found.   Ensure one of them exists, is readable by the webserver and contains the right password/username. Is it possible in Latex to make a triangular hat? The one that is used in math over three letters representing points to indicate a triangle.  Something like: Does iTunes Home Sharing transfer in-app purchases? My wife recently got an iPhone and, being that I'm an iPhone user already, I set up iTunes Home Sharing (under my Apple ID) so that I could share some of my purchased apps with her.  While paid apps transferred to her phone without a problem, in-app purchases that I had made under my account didn't transfer over.  Is this the correct behavior? Our phones are set up under different Apple IDs, but I was still able to transfer purchased (paid upfront) apps to her – which is completely allowed under the Terms of Use – so I assumed the same would apply to in-app purchases as well. Here are some tips for tagging questions. These guidelines will help you more accurately tag your questions, which in turn will help them get more attention and lead to better answers faster.     For more information, see "" in the . Is the Stack Overflow source code available? Does the series $\sum \limits _{n=0}^{\infty} \cos(n\pi)$ converge or diverge? Does the series $\sum \limits _{n=0}^{\infty} \cos(n\pi)$ converge or diverge?   On substituting values I get alternate $1$ and $-1$.    So taking sum of infinite GP, I get $\dfrac 1 2$. So it looks like it converges. When I try to connect to servers or join up on lan worlds in Minecraft it says "Failed to Login : Invalid session (Try restarting your game)". Multiplayer used to work fine but now keeps coming up with this error. Can anybody help? What system monitoring tools are available? I am looking for system monitoring tools which are GUI and CLI or web-based which include basic functions such as:   CPU Usage Ram Usage Swap Usage Disk Usage ( Space / I/O ) Heat Monitoring   I know there are many tools I can use, but I am looking for a single tool that has these basic functions. Can Hooke's law be derived? Can we derive  from the theory of elasticity? I know it is not a fundamental law and therefore can be derived from more basic considerations. Will airlines compensate me if my entertainment system is not working? In long haul flights, if I get a seat and after take off I found out that entertainment system is not working, I asked a flight attendant to change my seat but she apologized because there are no empty seats to move to.   Is it common to ask for a compensation for such an inconvenience? do major airlines compensate you in such cases? How to create a generic array in Java? Restrictions on the variables for this identity are as follows: $a \geq m \geq 0$ and $n \geq b \geq 0$.  I have not gotten far with this, but these are my very rudimentary thoughts: We need to define a special element, somehow, and then carve up the $m + n$ remaining elements to be chosen out of the remaining pool of $a + b$ elements by writing $a + b = a - i + b + i$. From the $a - i$ pile, we choose $m$ things. From the $b + i$ pile, we choose $n$ things. My problem is, what is going on with this special element? How is it being defined so as to split things in this precise way?  A hint would be great for the moment.