function getXmlHttp(){
  var xmlhttp;
  try {
    xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
  } catch (e) {
    try {
      xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
    } catch (E) {
      xmlhttp = false;
    }
  }
  if (!xmlhttp && typeof XMLHttpRequest!='undefined') {
    xmlhttp = new XMLHttpRequest();
  }
  return xmlhttp;
}

function validate()
{
	myform = document.autorization;
	login = myform.username.value;
	pass = myform.password.value;
	if (login == '' || pass == '')
		alert('Вы не заполнили все обязательные поля!');
	else
	{
		var req = getXmlHttp()  
		req.onreadystatechange = function() {  
			if (req.readyState == 4) { 
				if(req.status == 200) {
					if (req.responseText=='')
						myform.submit();
					else
						alert(req.responseText);
				}
			}
		}
		req.open('GET', 'http://dipifr.com/ajax/autoriz.php?login=' + login + '&pass=' + pass, true);  
		req.send(null);
	}
}

function keycode(e)
{
if(window.event)
	{
	keynum = e.keyCode;
	}
else if(e.which)
	{
	keynum = e.which;
	}
	if (keynum==13) validate();
}