function ajax_replace_content(url, id)
{
	element = document.getElementById(id)
	ajax_request(url, function(content)
	{
		element.innerHTML = content;
	});
}

function ajax_request(url, complete) {
        var http_request = false;

        if (window.XMLHttpRequest) { // Mozilla, Safari, ...
            http_request = new XMLHttpRequest();
            if (http_request.overrideMimeType) {
                http_request.overrideMimeType('text/xml');
                // See note below about this line
            }
        } 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('Giving up :( Cannot create an XMLHTTP instance');
            return false;
        }
        http_request.onreadystatechange = function(request) {
		if(http_request.readyState == 4){
			complete(http_request.responseText)
		}
	};
        http_request.open('GET', url, true);
        http_request.send(null);
}