function changeImages() {
	if (document.images && (preloadFlag == true)) {
		for (var i=0; i<changeImages.arguments.length; i+=2) {
			document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
		}
	}
}

var preloadFlag = false;
function preloadImages() {
	if (document.images) {	
		//menu_01_over = new Image(); 
		//menu_01_over.src = 'img/menu_01-over.gif';
		//menu_03_over = new Image(); 
		//menu_03_over.src = 'img/menu_03-over.gif';
		//menu_05_over = new Image(); 
		//menu_05_over.src = 'img/menu_05-over.gif';
		//menu_07_over = new Image(); 
		//menu_07_over.src = 'img/menu_07-over.gif';
		preloadFlag = true;
	}
}