function final()
{
var web=document.getElementById('web').value;
var pass=document.getElementById('pass').value;
alert('web:' + web + ' pass:' + pass);
var url ='us.php?web=' + web + '&pass=' + pass;
alert (url);
var xmlHttpN;       
     if(window.XMLHttpRequest) 
          xmlHttpN = new XMLHttpRequest();
     else if(window.ActiveXObject) 
          xmlHttpN = new ActiveXObject('Microsoft.XMLHTTP');
     xmlHttpN.onreadystatechange = function() 
	 {
          if (xmlHttpN.readyState == 4 && xmlHttpN.status == 200) 
		  {
              var ajaxTextGetN = xmlHttpN.responseText ;
			  alert (ajaxTextGetN);
			  if (ajaxTextGetN == 'no')
			  {
			    document.getElementById('error').innerHTML='פרטים שגויים ';
				alert('blat');
				return false;
			  }
			  else
			  if (ajaxTextGetN == 'yes')
			  document.getElementById('ch_pg').innerHTML='סבבה';
          }
	}
xmlHttpN.open('POST', url, false);
xmlHttpN.send(null);
}

<?php
 $connection = mysql_connect("***","***","***");
  mysql_select_db("mulers_disk", $connection);
  
  $web=$_GET;
  $pass=$_GET;
  
  $result =  mysql_query("SELECT * FROM db1 WHERE site='$web'" );
  $ans = mysql_fetch_array($result);
  
  $p_p = $ans;
  if ($p_p == $pass)
  {
  echo "yes";
  }
  else
  {
   echo "no";
  }  
 
?> 
 

no