function preLoadImg(imgFile){
	var image = new Image();
	image.src=imgFile;

	image.onload = function(){
		return true;
	};
	image.onerror = function(){
		return false;
	};
}

function addEvent(objeto, TipoEvento, funcao){
	if(objeto.addEventListener){ // todos navegadores menos IE
		objeto.addEventListener(TipoEvento, funcao, false);
		return true;
	} else if (objeto.attachEvent){ // IE
		var r = objeto.attachEvent('on'+TipoEvento, funcao);
		return r;
	} else {
		return false;
	}
}

function cursorWait(){
	document.body.style.cursor = 'wait';
	var wait = document.getElementById('wait'); 
	if(wait!=undefined){
		wait.style.display = 'block';
	}
}
function cursorNormal(){	
	document.body.style.cursor = 'default';
	var wait = document.getElementById('wait'); 
	if(wait!=undefined){
		wait.style.display = 'none';
	}
}
function gravar(formName){
	var form = $(formName);
	var params = form.serialize(true);
	cursorWait();
	new Ajax.Request('/grava.php', {
		method:'post',
		parameters: params,
		onSuccess: function(transport) {
			cursorNormal();
			if(transport.responseText.strip() == ''){				
				if(form.execute!=undefined){
					eval(form.execute.value);
				}
				if(form.goto!=undefined){
					window.location = form.goto.value;
				}
			}else{
				window.alert("Ocorreu um erro na gravação\n" + transport.responseText.stripTags());
			}
		},
		onFailure: function(transport) {
			cursorNormal();
			window.alert("Ocorreu um erro na gravação\n" + transport.responseText.stripTags()); 
		}
	});	
}