function createRequestObject() {
    var ro;
    var browser = navigator.appName;
    if(browser == "Microsoft Internet Explorer"){
        ro = new ActiveXObject("Microsoft.XMLHTTP");
    }else{
        ro = new XMLHttpRequest();
    }
    return ro;
}

var http = createRequestObject();

function setVendors(obj)
{

	var url = "/store/_ajax.php";
	var data = "action=setVendors&categoryID=" + obj.value;
	http.open("POST", url, true);
	http.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
    http.send(data);
	http.onreadystatechange = showVendors;

}

function setProducts()
{

	var categoryID = document.forms.searchform.product_category.value;
	var vendorID = document.forms.searchform.product_vendor.value;	

	var url = "/store/_ajax.php";
	var data = "action=setProducts&categoryID=" + categoryID + "&vendorID=" + vendorID;
	http.open("POST", url, true);
	http.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
    http.send(data);
	http.onreadystatechange = showProducts;

}

function showVendors() {

  if (http.readyState == 4) {
 
    if (http.responseText.indexOf('invalid') == -1) {
      qresults = http.responseText.split("---!---");
	  var count = qresults.length;
	  	  
		  var selbox = document.forms.searchform.product_vendor;
     	  selbox.options.length = 0;	   
			for (var i=0;i<qresults.length;i++)
			{
		      details = qresults[i].split("+++");
			  selbox.options[selbox.options.length] = new Option(details[0],details[1]);		      
			}

    }
    
	setProducts();    

	}
	

	
}

function showProducts() {

  if (http.readyState == 4) {
 
    if (http.responseText.indexOf('invalid') == -1) {
      qresults = http.responseText.split("---!---");
	  var count = qresults.length;
	  	  
		  var selbox = document.forms.searchform.product_name;
     	  selbox.options.length = 0;	   
			for (var i=0;i<qresults.length;i++)
			{
		      details = qresults[i].split("+++");
			  selbox.options[selbox.options.length] = new Option(details[0],details[1]);		      
			}

    }

	}
}