function getXmlHttpRequestObject() {
	if (window.XMLHttpRequest) {
		return new XMLHttpRequest();
	} else if(window.ActiveXObject) {
		return new ActiveXObject("Microsoft.XMLHTTP");
	} else {
		alert("It's about time to upgrade you browser don't you think?");
	}
}


var getReq = getXmlHttpRequestObject();


function open_submenu(brand)
{
	if (getReq.readyState == 4 || getReq.readyState == 0) {
                var rand  = Math.random();
		getReq.open("GET", 'submenu.php?brand='+brand+'&rand='+rand, true);
		getReq.onreadystatechange = get_submenu_request;
		getReq.send(null);
		}
}


function get_submenu_request()
{
	if (getReq.readyState == 4) document.getElementById('top_navigation_submenu').innerHTML=getReq.responseText;
}


function replace_big_picture(id,source)
{
document.getElementById(id).innerHTML='<img src="'+source+'" />';
}


function jsRate(value, id)
{
		document.getElementById(id).value=value;
		var echo_val=value*17;
		document.getElementById('rating_layer').innerHTML ='';
		document.getElementById('rating_layer').innerHTML ='<ul class="unit-rating"><li class="current-rating" style="width:'+echo_val+'px;">'+echo_val+'</li><li><a href="#" title="Bad" class="r1-unit"  onclick="jsRate(\'1\', \''+id+'\'); return false;">1</a></li><li><a href="#" title="Poor" class="r2-unit" onclick="jsRate(\'2\', \''+id+'\'); return false;">2</a></li><li><a href="#" title="Fair" class="r3-unit" onclick="jsRate(\'3\', \''+id+'\'); return false;">3</a></li><li><a href="#" title="Good" class="r4-unit" onclick="jsRate(\'4\', \''+id+'\'); return false;">4</a></li><li><a href="#" title="Excellent" class="r5-unit" onclick="jsRate(\'5\', \''+id+'\'); return false;">5</a></li></ul>';
}



function ajaxRate(value,number)
{
	if (getReq.readyState == 4 || getReq.readyState == 0) {
                var rand  = Math.random();
		getReq.open("GET", '/product_rate.php?number='+number+'&value='+value+'&rand='+rand, true);
		getReq.onreadystatechange = ajaxRate_request;
		getReq.send(null);
	}
}


function ajaxRate_request()
{
	if (getReq.readyState == 4) {
		var str = getReq.responseText;
		document.getElementById('rating_layer').innerHTML=str;
	}
}