function getAjaxObj() {
	var xmlHttp;
	try {
		xmlHttp = new XMLHttpRequest();// Firefox, Opera 8.0+, Safari
    } catch (e) {
    	// Internet Explorer
    	try {
			xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
		} catch (e) {
			try {
				xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
        	} catch (e) {
        		alert("Your browser does not support AJAX!");
        		return false;
			}
		}
	}
	return xmlHttp;
}


function getContentByAjax(element_id, url) {
        var xh = getAjaxObj();  
        if (!xh) return;
        xh.onreadystatechange=function() {
                if(xh.readyState == 4) {
                        var obj = document.getElementById(element_id);
                        if (obj){
                                obj.innerHTML = xh.responseText;                                
                        }                                       
                }
        }       
        xh.open("GET", url, true);      
        xh.send(null);
}