function validate_form(thisform)
{

  var uname = thisform.username.value;
  if (uname==null||uname=="")
      {alert("Please Enter Name.");return false;}

  var eamail = thisform.email.value;
  var apos=eamail.indexOf("@");
  var dotpos=eamail.lastIndexOf(".");
  if (apos<1||dotpos-apos<2)
      {alert("Please Enter a valid email address.");return false}
    
  var pass = thisform.password.value;
  if (pass==null||pass=="")
      {alert("Please Enter a Password.");return false;}

  var cpass = thisform.cpassword.value;
  if (pass!=cpass)
      {alert("Passwords do not match.");return false;}
    
  return true;
}