function somenteNumero(e)
{
	var tecla=(window.event)?event.keyCode:e.which;
	if((tecla > 47 && tecla < 58)) 
		return true;
	else{
		if (tecla != 8 && tecla != 0) 
			return false;
		else 
			return true;
	}
}


function mascara(obj,next, tam)
{
	proximo = document.getElementById(next);
	if(obj.value.length == tam)
		proximo.focus();
}