One of the members in the forum (forums.asp.net) is asking how to limit the number of selected items in the ListBox and so contributors (including me) gave the OP (Original Poster) different ideas on how to validate it. Some of them provided solution using pure JavaScripts and a mixture of code behind and JavaScript. However the OP doesn’t want to use JavaScript validation for some reason, so I decided to post the solution that I have provided on that thread as a reference to others. Here it is: ......