http://forums.asp.net/1007.aspxThis forum is the place for ASP.NET AJAX 'getting started' questions, general questions that don't fit in one of the other forums about AJAX enCommunityServer 2007 SP1 (Build: 20510.895)http://forums.asp.net/thread/3273209.aspxFri, 03 Jul 2009 09:46:53 GMT4c671506-2930-414c-a40b-8bf57ded5924:3273209mudassarkhanmudassarkhan0http://forums.asp.net/thread/3273209.aspxhttp://forums.asp.net/commentrss.aspx?SectionID=1007&PostID=3273209<p>&nbsp;Refer here</p> <p><a href="http://www.aspsnippets.com/post/2009/02/03/Check-whether-username-already-exists.aspx">http://www.aspsnippets.com/post/2009/02/03/Check-whether-username-already-exists.aspx</a></p>http://forums.asp.net/thread/3272696.aspxFri, 03 Jul 2009 05:18:50 GMT4c671506-2930-414c-a40b-8bf57ded5924:3272696CraigLCraigL0http://forums.asp.net/thread/3272696.aspxhttp://forums.asp.net/commentrss.aspx?SectionID=1007&PostID=3272696<p>Hi Guys,</p><p>I have a user registration form, and would like to have a background Username checker.. That is, once the user exits the txtUsername TextBox, a background action happens, which checks if the Username already exists. I&#39;m no Ajax or Asp.Net guru (yet), but could someone help me out with either ideas, or a link to where this might be explained?</p><p>I think Ajax will do it for me, somehow, but not sure.</p><p>The user should be able to carry on using the site while the check happens, so a postback (and subsiquent refresh of the screen) isn&#39;t really an option.</p><p>Thanks.<br /></p>