// DROPDOWN VISIBILITY FLAGS

var dropdownCount = 6;
var dropdownVisibility = new Array(dropdownCount+1);
for (var i = 1; i <= dropdownCount; i++) {
	dropdownVisibility[i] = false;
}

// EVENT HANDLER FUNCTIONS

function mouseOverEvent(dropdownId, buttonId) {
	//imageSwapOn(document.getElementById("nav_button_"+dropdownId+"_"+buttonId));
	dropdownVisibility[dropdownId] = true;
	updateDropdownVisibility(dropdownId);
}

function mouseOutEvent(dropdownId, buttonId) {
	//imageSwapOff(document.getElementById("nav_button_"+dropdownId+"_"+buttonId));
	dropdownVisibility[dropdownId] = false;
	setTimeout("updateDropdownVisibility("+dropdownId+")", 250);
}

// IMAGE SWAP FUNCTIONS

function imageSwapOn(imageElement) {
	imageElement.src = imageElement.src.replace(/.gif/g, "_o.gif");
}

function imageSwapOff(imageElement) {
	imageElement.src = imageElement.src.replace(/_o.gif/g, ".gif");
}

// DROPDOWN MENU FUNCTIONS

function updateDropdownVisibility(dropdownId) {
	var dropdownElement = document.getElementById("dropdown_menu_"+dropdownId);
	if (dropdownVisibility[dropdownId]) {
		dropdownElement.style.visibility = "visible";
	} else {
		dropdownElement.style.visibility = "hidden";
	}
}