var isMenuVisible = true;

	function showHideMenu() {
		
		var menu = document.getElementById('mainMenu');
		var showHideImage = document.getElementById('showHideImage');
		var showHideText = document.getElementById('showHideText');
		
		if (isMenuVisible) {
			menu.style.display = 'none'; 
			showHideImage.src = 'images/show_menu.gif';
			showHideText.innerHTML = "Show Menu";
					
		} else {
			menu.style.display = 'block'; 
			showHideImage.src = 'images/hide_menu.gif';
			showHideText.innerHTML = "Hide Menu";
			
		}
		
		isMenuVisible = !isMenuVisible;
		
	}