/*************************************************
	changeVisibility()

		changes the visibility of the various
		buttons in the Button Menu
*************************************************/

(document.layers) ? layerobject=true : layerobject=false;
(document.all) ? allobject = true : allobject = false;
(document.getElementById) ? dom = true : dom = false;

function changeScheduleVisibility(id,action)
{
    switch (action)
    {
	case "show":
		if (layerobject) {
			if (id == "none"){
				document.layers['schedule_casey'].visibility = "hide";
				document.layers['schedule_dave'].visibility = "hide";
				document.layers['schedule_ethan'].visibility = "hide";
				document.layers['schedule_jeffrey'].visibility = "hide";
				document.layers['schedule_kamil'].visibility = "hide";
				document.layers['schedule_tilman'].visibility = "hide";
			}
			else if (id == "all") {
				document.layers['schedule_casey'].visibility = "show";
				document.layers['schedule_dave'].visibility = "show";
				document.layers['schedule_ethan'].visibility = "show";
				document.layers['schedule_jeffrey'].visibility = "show";
				document.layers['schedule_kamil'].visibility = "show";
				document.layers['schedule_tilman'].visibility = "show";
			}
			else {
				document.layers[''+id+''].visibility = "show";
			}
		}
		else if (allobject) {
			if (id == "none"){
				document.all['schedule_casey'].style.visibility = "hidden";
				document.all['schedule_dave'].style.visibility = "hidden";
				document.all['schedule_ethan'].style.visibility = "hidden";
				document.all['schedule_jeffrey'].style.visibility = "hidden";
				document.all['schedule_kamil'].style.visibility = "hidden";
				document.all['schedule_tilman'].style.visibility = "hidden";
			}
			else if (id == "all") {
				document.all['schedule_casey'].style.visibility = "visible";
				document.all['schedule_dave'].style.visibility = "visible";
				document.all['schedule_ethan'].style.visibility = "visible";
				document.all['schedule_jeffrey'].style.visibility = "visible";
				document.all['schedule_kamil'].style.visibility = "visible";
				document.all['schedule_tilman'].style.visibility = "visible";
			}
			else {
				document.all[''+id+''].style.visibility = "visible";
			}
		}
		else if (dom) {
			if (id == "none"){
				document.getElementById('schedule_casey').style.visibility = "hidden";
				document.getElementById('schedule_dave').style.visibility = "hidden";
				document.getElementById('schedule_ethan').style.visibility = "hidden";
				document.getElementById('schedule_jeffrey').style.visibility = "hidden";
				document.getElementById('schedule_kamil').style.visibility = "hidden";
				document.getElementById('schedule_tilman').style.visibility = "hidden";
			}
			else if (id == "all"){
				document.getElementById('schedule_casey').style.visibility = "visible";
				document.getElementById('schedule_dave').style.visibility = "visible";
				document.getElementById('schedule_ethan').style.visibility = "visible";
				document.getElementById('schedule_jeffrey').style.visibility = "visible";
				document.getElementById('schedule_kamil').style.visibility = "visible";
				document.getElementById('schedule_tilman').style.visibility = "visible";
			}
			else {
				document.getElementById(''+id+'').style.visibility = "visible";
			}
		}
		break;

    default:return;
    } // end of switch statement

  return;
} // end of function changeVisibility()