// ajax_order_nr():
// creates a GET-Request for url and returns the info into the element specified by an id
// id2 is the id of the element which is order_nr

function ajax_order_nr(url, id, id2){	
	//erstellen des requests
	var req = null;
	if(document.getElementById(id2) != null){
		var check_value = document.getElementById(id2).value;
		if(url.indexOf('?') == -1){
			url = url + "?sub_from=" + check_value;
		} else {
			url = url + "&sub_from=" + check_value;
		}
	}
	
	try{
		req = new XMLHttpRequest();
	} catch (ms){
		try{
			req = new ActiveXObject("Msxml2.XMLHTTP");
		} catch (nonms){
			try{
				req = new ActiveXObject("Microsoft.XMLHTTP");
			} catch (failed){
				req = null;
			}
		}
	}
	
	//anfrage erstellen (GET)
	//request ist asynchron
	req.open("GET", url, true);

	//Beim abschliessen des request wird diese Funktion ausgefuehrt
	req.onreadystatechange = function(){
		switch(req.readyState) {
			case 4:
				if(req.status == 200) {
					if(document.getElementById(id) != null){
						document.getElementById(id).innerHTML = req.responseText;
					}
				} else {
					alert('Error ' + req.status+ ': Please provide an internet connection.');
				}
			break;
			default:
				return false;
			break; 
		}
	};
	
	req.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
	req.send(null);
}