var http_request = false;
   function makePOSTRequest(url, 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;
      }
      http_request.onreadystatechange = alertContents;
      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() {
      if (http_request.readyState == 4) {
         if (http_request.status == 200) {		
            result = http_request.responseText;
            document.getElementById(span).innerHTML = result;            
         } else {
            alert('There was a problem with the request.');
         }
      }
   }
   
   function ajax(span1,page,poststr){
		span = span1;
		 var poststr = poststr;		
		makePOSTRequest(page, poststr);		
   }
   
   function preload(id){
	document.getElementById(id).innerHTML = "";
   }        
   	
   function hide(id){		
		document.getElementById(id).innerHTML = "";   
   }