// Home Page Navigation
// By: Patrick G. Dooley

// this global is used to determine which tab to hide, or whether it is the same tab and do nothing.
var previousTab = false;

function tabFunction(subNavID){
	var currentTab=subNavID;
	// set the prior tab back to static state
	if(previousTab != false && previousTab != currentTab){
		var leftTab = previousTab + "-left_corner";
		var rightTab = previousTab + "-right_corner";
		var centerTab = "TD_BG-" + previousTab;
		document.getElementById(previousTab).style.display="none";
		document.getElementById(leftTab).src="/include/nav_graphics/static_tab_left.jpg";
		document.getElementById(rightTab).src="/include/nav_graphics/static_tab_right.jpg";
		document.getElementById(centerTab).className="static";
	}
	// if it is the same tab then do nothing - no flicker
	else if(previousTab==currentTab){
	return false;
	}
	// set the active tab
	var leftTab = currentTab + "-left_corner";
	var rightTab = currentTab + "-right_corner";
	var centerTab = "TD_BG-" + currentTab;
	document.getElementById(currentTab).style.display="block";
	document.getElementById(leftTab).src="/include/nav_graphics/active_tab_left.jpg";
	document.getElementById(rightTab).src="/include/nav_graphics/active_tab_right.jpg";
	document.getElementById(centerTab).className="active";
	
	previousTab = currentTab;
}