var regexEmail = new RegExp ("^([a-zA-Z0-9_\\-\\.]+)@((\\[[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}\\.)|(([a-zA-Z0-9\\-]+\\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\\]?)$");
var regexNumero= new RegExp ("^[0-9]+$", "g");


//valida se o objecto contem um texto composto s por numeros
function ValidaInteiro(oObj)
{
	return !!oObj.value.match(regexNumero)
}
//valida se o objecto contem um texto composto por um email vlido
function ValidaEmail(oObj)
{
	return !!oObj.value.match(regexEmail)
}

//valida se o objecto contem texto
function ValidaTexto(oObj)
{
	return oObj.value.length>0
}

function CancelaEvento(oEvent)
{
	if(!oEvent)
		oEvent = window.event;
	if(!oEvent)
	{
		var oStackEvent = null;
		var oCaller = window.CancelaEvento.caller;
		while (oCaller)
		{
			var oStackEvent = oCaller.arguments[0];
			if (oStackEvent && oStackEvent.constructor == Event)
				break;
			oCaller = oCaller.caller;
		}
		oEvent = oStackEvent;
	}
	if(oEvent)
	{
		//Trickling(netscape) VS bubbling(ms)
		oEvent.cancelBubble = true;//IE
		if(oEvent.stopPropagation)oEvent.stopPropagation(); //!IE
		
		//default behavior
		oEvent.returnValue = false;//IE
		if(oEvent.preventDefault)oEvent.preventDefault(); //!IE
		return false;
	}
}