Email Validation using Javascript with Dotnet

var emailPat = "^[\\w-_\.]*[\\w-_\.]\@[\\w]\.+[\\w]+[\\w]$";  var emailid=document.getElementById("ctl00$ContentPlaceHolder1$txtEmail").value;  var matchArray = emailid.match(emailPat);  if(matchArray == null)  {       alert("Please Enter Propoer EmailID");       document.getElementById('ctl00$ContentPlaceHolder1$txtEmail').focus();       return false;   }