var please_wait = "<center><img src='/imagens/carregando.gif'></center>";

function ajax_exec(url,target) {
 	if ( ! document.getElementById) {
  		return false;
 	}

 	if (please_wait != null) {
  		document.getElementById(target).innerHTML = please_wait;
 	}

 	if (window.ActiveXObject) {
  		link = new ActiveXObject("Microsoft.XMLHTTP");
 	} else if (window.XMLHttpRequest) {
  		link = new XMLHttpRequest();
 	}

 	if (link == undefined) {
  		return false;
 	}
 	link.onreadystatechange = function() { response_exec(url,target); }
 	link.open("GET", url, true);
 	link.send(null);
}
function response_exec(url,target) {
 	if (link.readyState == 4) {
			
			if(link.status == 200){
				eval(link.responseText);
				document.getElementById(target).innerHTML = '';
				return false;
			}else{
				alert("Página não encontrada! " + link.status);
				return true;
			}
	}
}
function set_loading_message_exec(msg) {
 	please_wait = msg;
}