function carregaCidade(divId, elementId, id_uf){

		var ajax = criarAjax();
		if(ajax){

			ajax.open("GET", "carregaCidade.php?id_uf=" + id_uf, true);
			ajax.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");

			ajax.onreadystatechange = 
				function state(){

					if (ajax.readyState < 4)
					{	
						document.getElementById(divId).innerHTML = '<select name="' + elementId + '" id="' + elementId + '"><option>Carregando...</option></select>';
					}
					if (ajax.readyState == 4)
					{
						if (ajax.status == 200)
						{
							document.getElementById(divId).innerHTML =
                            '<select name="' + elementId + '" id="' + elementId + '">' + 
                            ajax.responseText + '</select>';
						}
					} 
				}


		ajax.send(null);
		}



	}


	function criarAjax(){
		var ajax;

		//verifica se o browser tem suporte a ajax
		try{
			ajax = new ActiveXObject("Microsoft.XMLHTTP");
		}
		catch (e){
			try{
				ajax = new ActiveXObject("Msxml2.XMLHTTP");
			}
			catch (ex){
				try{
					ajax = new XMLHttpRequest();
				}
				catch (exc){
					alert("Esse browser nãsuporta AJAX");
					ajax = null;
				}
			}
		}
		return ajax;
	}