// JavaScript Document
<script language="javascript">
function checkfield(loginform)
{

if(loginform.Description.value=="")
    {
        alert("Please Enter Description."); 
        loginform.Description.focus();
        return false;
    }
    if(loginform.S_name.value=="")
    {
        alert("Please Enter Your Name.");
        loginform.S_name.focus ();
        return false;
    }
    
    if (loginform.S_email.value == "")
    {
        alert("Please Enter a valid Email address.");
        loginform.S_email.focus();
        return false; 
    }
    
    if (!isEmailAddr(loginform.S_email.value))
    {
        alert("Please Enter a valid Email address E.g. : yourname@yourdomain.com");
        loginform.S_email.focus();
        return false;
    }    
    
    return true;
}

function isEmailAddr(S_email)
{
  var result = false
  var theStr = new String(S_email)
  var index = theStr.indexOf("@");
  if (index > 0)
  {
    var pindex = theStr.indexOf(".",index);
    if ((pindex > index+1) && (theStr.length > pindex+1)
    result = true;
  } 
  return result;
}
</script>