/* onchange_url():
 * Onchange of Element, it will go to the url and will set the field-variable as GET with new value
 * url -> base-url to go to
 * field -> id of field which will be change 
 * 
 */

function onchange_url(url, field){
	var url = url;
	var f = document.getElementById(field);
	
	if(url.indexOf("?") > 0){
		window.location.href = url + "&" + field + "=" + f.value;
	} else {
		window.location.href = url + "?" + field + "=" + f.value;
	}
}