function checkEmail( email ){
 return ( email.search(/^[A-Za-z0-9-\._]*@[A-Za-z0-9-\._]*\.[A-Za-z]{1,4}$/)==0?true:false);
}

function field_empty(str) {
for (var i = 0; i < str.length; i++)
     if (" " != str.charAt(i))
  return false;
     return true;
}

function checkform_v2(f) {
  var errMSG = "";
  for (var i = 0; i<f.elements.length; i++)
    if ( f.elements[i].getAttribute("required") && !f.elements[i].disabled )
	if (field_empty(f.elements[i].value)) // пустой
	    errMSG += " " + f.elements[i].title + "\n";
	if ("" != errMSG) {
	    alert("Не заполнены обязательные поля:\n" + errMSG);
	    return false;
	}
  if (f.email && !checkEmail(f.email.value)){alert("Неверный e-mail");return false;}
  return true;
}

function addEvent(obj,EventType,fn,useCapture){  
  if(obj!=null){
     if(obj.addEventListener){
        obj.addEventListener(EventType,fn,useCapture);
        return true;
     }
     else if(obj.attachEvent){
        obj.attachEvent('on'+EventType,fn);
        return true;
     }
  }
  return false;
  }