function isEmail(fld)
// This function do some email address validation.
// Also convert to lowercase when valid
// to use    <input name=text1 onchange="return isEmail(this)">
{
    var reg = /^([A-Za-z0-9_\-\.])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/;
    var address = fld.value;
    if(reg.test(address) == false) {
      alert('Invalid Email Address');
      return false;
   }
   return true;
}