function MascaraData()
{
//usar no evento keypress
//bloqueia caracteres alfa e coloca as barras nas posições

	with(window.event.srcElement)
	{
		maxLength = 10
		if(event.keyCode < 48 || event.keyCode > 57)
			{event.returnValue = false;}	
		if((value.length == 2 || value.length == 5) && event.keyCode != 8)
			{value += "/";}
	}
}