function mascara(e,src,mask)
	{
		if(window.event)
			{
				_TXT = e.keyCode;
			}
		else if(e.which)
			{
				_TXT = e.which;
			}
		if(_TXT > 47 && _TXT < 58)
			{
				var i = src.value.length;
				var saida = mask.substring(0,1);
				var texto = mask.substring(i)
				 if (texto.substring(0,1) != saida)
					{
						src.value += texto.substring(0,1);
					}
				return true;
			}
		else
			{
				if (_TXT != 8)
					{
						return false;
					}
				else
					{
						return true;
					}
			}
	}