var loadstatustext="<div align='center' style='height:20px; vertical-align:middle' ><img src='images/loading.gif'/></div>"
var http_request = false;
   function makePOSTRequest(url, myspan, parameters) {
      http_request = false;
      if (window.XMLHttpRequest) { // Mozilla, Safari,...
         http_request = new XMLHttpRequest();
         if (http_request.overrideMimeType) {
         	// set type accordingly to anticipated content type
            //http_request.overrideMimeType('text/xml');
            http_request.overrideMimeType('text/html');
         }
      } else if (window.ActiveXObject) { // IE
         try {
            http_request = new ActiveXObject("Msxml2.XMLHTTP");
         } catch (e) {
            try {
               http_request = new ActiveXObject("Microsoft.XMLHTTP");
            } catch (e) {}
         }
      }
      if (!http_request) {
         alert('Cannot create XMLHTTP instance');
         return false;
      }
	  
document.getElementById(myspan).innerHTML=loadstatustext ;

http_request.onreadystatechange=function(){
alertContents(http_request, myspan);
}      
      //http_request.onreadystatechange = alertContents(http_request, myspan);
      http_request.open('POST', url, true);
      http_request.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
      http_request.setRequestHeader("Content-length", parameters.length);
      http_request.setRequestHeader("Connection", "close");
      http_request.send(parameters);
   }

   function alertContents(http_request, myspan) {
      if (http_request.readyState == 4) {
         if (http_request.status == 200) {
            //alert(http_request.responseText);
            result = http_request.responseText;
            document.getElementById(myspan).innerHTML = result;            
         } else {
            alert('There was a problem with the request.');
         }
      }
   }
   
   function getlogin(obj) {
      var poststr = "username=" + encodeURI( document.getElementById("f1").value ) +
                    "&password=" + encodeURI( document.getElementById("f2").value ) +
                    "&Login=" + encodeURI( document.getElementById("Login").value );
      makePOSTRequest('ajaxlogin.php', 'ajaxlog', poststr);
   }
   /*
   if we use "&" character it wont work...
but if we use escape();

var poststr = "mytextarea1=" + escape(encodeURI(
document.getElementById("mytextarea1").value )) +"&mytextarea2=" +
escape(encodeURI( document.getElementById("mytextarea2").value ));

and next in php u use urldecode , it will work good.   
   
   */