function validate(form_id, email){

   var reg = /^([A-Za-z0-9_\-\.])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/;
   var what = document.forms[form_id].elements[email];
   var address = what.value;
   var default_address = what.defaultValue;
   
   if(address == default_address){
	  alert(noemail);
	  what.focus();
      return false;
   }else if(reg.test(address) == false){
      alert(invalidemail);
	  what.focus();
      return false;
   }
   document.getElementById(form_id).submit();
}