function choose(object, screens)
{
	var elem = document.getElementById(object);
	var elem_screens = document.getElementById(screens);

	if(elem.className != "selected")
		{
			elem.className = "selected";
			elem_screens.checked = true;
		}
			else
		{
			elem.className = "notselect";
			elem_screens.checked = false;
		}
}