var preloaded = [];

for (var i = 1; i <= 5; i++) {
	preloaded[i] = [loadImage(i + "-0.gif"), loadImage(i + "-1.gif")];
}

function init() {
	if (mtDropDown.isSupported()) {
		mtDropDown.initialize();
		
		menu1.onactivate = function() { swapImage("button1", preloaded[1][1].src) };
		menu1.ondeactivate = function() { swapImage("button1", preloaded[1][0].src) };
		
		menu2.onactivate = function() { swapImage("button2", preloaded[2][1].src) };
		menu2.ondeactivate = function() { swapImage("button2", preloaded[2][0].src) };
		
		menu3.onactivate = function() { swapImage("button3", preloaded[3][1].src) };
		menu3.ondeactivate = function() { swapImage("button3", preloaded[3][0].src) };
		
		menu4.onactivate = function() { swapImage("button4", preloaded[4][1].src) };
		menu4.ondeactivate = function() { swapImage("button4", preloaded[4][0].src) };
		
		menu5.onactivate = function() { swapImage("button5", preloaded[5][1].src) };
		menu5.ondeactivate = function() { swapImage("button5", preloaded[5][0].src) };				
		
	}
}

function loadImage(sFilename) {
	var img = new Image();
	img.src ="popup1/" + sFilename;
	return img;
}

function swapImage(imgName, sFilename) {
	document.images[imgName].src = sFilename;
}