function makeHttpRequest(url, callback_function, return_xml)
{
	var ajaxRequest;

	if (window.XMLHttpRequest) 
	{ 
		// Mozilla, Safari,...
		ajaxRequest = new XMLHttpRequest();
       	
		if (ajaxRequest.overrideMimeType) 
		{
        	ajaxRequest.overrideMimeType('text/xml');
		}
	} 
	else if (window.ActiveXObject) 
	{ 
		// IE
		try 
		{
        	ajaxRequest = new ActiveXObject("Msxml2.XMLHTTP");
       	} 
		catch (e) 
		{
        	try 
			{
            	ajaxRequest = new ActiveXObject("Microsoft.XMLHTTP");
           	} 
			catch (e) {}
       	}
	}
	if (!ajaxRequest) 
   	{
		alert('Unfortunatelly you browser doesn\'t support this feature.');
       	return false;
   	}
   
	ajaxRequest.onreadystatechange = function() 
	{
		if (ajaxRequest.readyState == 4) 
		{
			if (ajaxRequest.status == 200) 
			{
				if (return_xml) 
				{
					eval(callback_function + '(ajaxRequest.responseXML)');
				}
				else
				{
					eval(callback_function + '(ajaxRequest.responseText)');
				}
			}
			else 
			{
				//alert('There was a problem with the request.(Code: ' + ajaxRequest.status + ')');
			}
		}
	}
	
	ajaxRequest.open('GET', url, true);
	ajaxRequest.send(null);
}


function loadBanner(xml)
{
    var html_content = xml.getElementsByTagName('content').item(0).firstChild.nodeValue;
    var reload_after = xml.getElementsByTagName('reload').item(0).firstChild.nodeValue;
    document.getElementById('ajax-banner').innerHTML = html_content;

    try 
	{
		clearTimeout(to);
    } 
	catch (e) {}

	to = setTimeout("nextAd()", parseInt(reload_after));
}


function nextAd()
{
    var now = new Date();
    var url = 'includes/ajax-banner.php?ts=' + now.getTime();
    makeHttpRequest(url, 'loadBanner', true);
}

window.onload = nextAd;