var req;
var acti;
var ftid;
var zen;
function filter_val(id, zid, act) {
  
  if(zid){
	 znid = '&zenid='+zid;
  }else{
	  znid = "";
  }
  acti = act;
  ftid = id;
  zen = zid;

 manuf = document.filter_search.manufacturers_id.options[document.filter_search.manufacturers_id.selectedIndex].value;

   var url="filter.php?acts="+act+"&fid="+id+znid+"&mid="+manuf;
	
   // Internet Explorer
   try { req = new ActiveXObject("Msxml2.XMLHTTP"); } 
   catch(e) { 
      try { req = new ActiveXObject("Microsoft.XMLHTTP"); } 
      catch(oc) { req = null; } 
   } 

   // Mozailla/Safari 
   if (!req && typeof XMLHttpRequest != "undefined") { req = new XMLHttpRequest(); } 

   // Call the processChange() function when the page has loaded 
   if (req != null) {
	   if(ftid != '' && acti == 'cates_filter'){
			document.filter_search.categories_id.options[0]=new Option("Searching....", "", true);
	   }else if(ftid != '' && acti == 'products_filter'){
		   document.filter_search.fpid.options[0]=new Option("Searching....", "", true);
	   }
      req.onreadystatechange = processChange; 
      req.open("GET", url, true); 
      req.send(null); 
   } 
}

function processChange() { 
   // The page has loaded and the HTTP status code is 200 OK 
   if (req.readyState == 4 && req.status == 200) { 
      // Write the contents of this URL to the searchResult layer 
	  if(ftid != '' && acti == 'cates_filter'){
		  getObject("catesshow").innerHTML = req.responseText;
		  filter_val(ftid, zen, 'products_manuf_filter');
	  }else if(ftid != '' && acti == 'products_manuf_filter'){
		  getObject("prodshow").innerHTML = req.responseText;
	  }else if(ftid != '' && acti == 'products_filter'){
		  getObject("prodshow").innerHTML = req.responseText;
	  }else if(ftid == '' && acti == 'cates_filter'){
		  getObject("catesshow").innerHTML = req.responseText;
		  filter_val('', zen, 'products_filter');
	  }else if(ftid == '' && acti == 'products_filter'){
		  getObject("prodshow").innerHTML = req.responseText;
	  }
   } 
}

function getObject(name) { 
   var ns4 = (document.layers) ? true : false; 
   var w3c = (document.getElementById) ? true : false; 
   var ie4 = (document.all) ? true : false; 

   if (ns4) return eval('document.' + name); 
   if (w3c) return document.getElementById(name); 
   if (ie4) return eval('document.all.' + name); 
   return false; 
}