function getCityList(id, block)
{
if (window.XMLHttpRequest)
  {// code for IE7+, Firefox, Chrome, Opera, Safari
  	xmlhttp=new XMLHttpRequest();
  }
else
  {// code for IE6, IE5
  	xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
  }
xmlhttp.onreadystatechange=function()
  {
  if (xmlhttp.readyState==4 && xmlhttp.status==200)
    {
    	document.getElementById(block).innerHTML=xmlhttp.responseText;
    }
  }
  
var url="getcity.php";
url=url+"?state_id="+id+"&selectid="+block;
xmlhttp.open("GET",url,true);
xmlhttp.send();
}