function TestEmail() {

Mail=document.EmailForm.email.value;
Mail=Mail.toLowerCase();

if (Mail.search(/^[a-zA-Z]+([_\.-]?[a-zA-Z0-9]+)*@[a-zA-Z0-9]+([\.-]?[a-zA-Z0-9]+)*(\.[a-zA-Z]{2,4})+$/ ) == -1){  
    document.EmailForm.email.value='incorrect emailadress....';
    document.EmailForm.email.focus();
    
    return false;
  } else {
    
    return true;
  }
}