function soNumero(keypress)
{
	if(keypress < 48 || keypress > 57 || keypress == 8 || keypress == 44 || keypress == 45){
		event.keyCode = 0;
		return false;
	}
	
}

function validaMail(campo){
	var str = campo.value;
	var filter = /^([\w-]+(?:\.[\w-]+)*)@((?:[\w-]+\.)*\w[\w-]{0,66})\.([a-z]{2,6}(?:\.[a-z]{2})?)$/i;
	if(filter.test(str))
		valido = true;
	else {
		alert("Email inválido!");
		campo.focus();
		valido = false;
	}
	return valido;
}