// functions for manipulating drop-down menus

// The menu array contains all the names of the ids for the elements that call/trigger drop-down menus
function MenuNav(ID, Left, TabID, TabColour, IsVisible) {
		this.ID = ID; //ID of the hidden drip-down
		this.Left = Left; // left position
		this.TabID = TabID; // ID of menu tab (which is always visible)
		this.TabColour = TabColour; // roll-over colour of menu tab
		this.IsVisible = IsVisible; // flag, to show whether frop-down is visible
}

var Menus = new Array(1);
			
Menus[0] = new MenuNav("Menu_Services", "200px", "Services", "#01BA9E", false);

function ShowPullDown(ID) {
	if (document.getElementById(ID)) {
		for (var i = 0; i < Menus.length; i++) {
			if (ID == Menus[i].ID) {
				document.getElementById(ID).style.left = Menus[i].Left;
				if (!Menus[i].IsVisible) {
					if (document.getElementById(Menus[i].TabID)) {
						var OldColour = document.getElementById(Menus[i].TabID).style.color;
						document.getElementById(Menus[i].TabID).style.color = Menus[i].TabColour;
						Menus[i].TabColour = OldColour;
					}
					Menus[i].IsVisible = true;
				}
			}
		}
	}
}

// Hides the pull down menu (or all pull-down menus), 
//and resets the menu tab (which remains visible to its original colour
function HidePullDown (ID) {
	if (ID == 'All') {
		for (var i = 0; i < Menus.length; i++) {
			if (document.getElementById(Menus[i].ID) && Menus[i].IsVisible) {
				document.getElementById(Menus[i]).style.left = "-999em";
				if (document.getElementById(Menus[i].TabID)) {
					var OldColour = document.getElementById(Menus[i].TabID).style.color;
					document.getElementById(Menus[i].TabID).style.color = Menus[i].TabColour;
					Menus[i].TabColour = OldColour;
				}
				Menus[i].IsVisible = false;
			}
		}
	} else {
		for (var i = 0; i < Menus.length; i++) {
			if (Menus[i].ID == ID && document.getElementById(Menus[i].ID) && Menus[i].IsVisible) {
				document.getElementById(Menus[i].ID).style.left = "-999em";
				if (document.getElementById(Menus[i].TabID)) {
					var OldColour = document.getElementById(Menus[i].TabID).style.color;
					document.getElementById(Menus[i].TabID).style.color = Menus[i].TabColour;
					Menus[i].TabColour = OldColour;
				}
				Menus[i].IsVisible = false;
			}
		}
	}	
}