function changeMenu( imgNum ) {

	if( document.all && document.images ) {
		for( var i = 1; i <= 6; i++ ) {
			if( document.all[ "m" + i ].menu == "true" ) {
				document.all[ "submenu" + i ].style.display = "none";
			}
		}
	}

	switch( imgNum ) {
		case 1: {
			document.images.menu1.src = 'images/menu/part1_ro.gif';
			showSubmenu( imgNum );
			return;
		}
		case 2: {
			document.images.menu2.src = 'images/menu/part2_ro.gif';
			showSubmenu( imgNum );
			return;
		}
		case 3: {
			document.images.menu3.src = 'images/menu/part3_ro.gif';
			showSubmenu( imgNum );
			return;
		}
		case 4: {
			document.images.menu4.src = 'images/menu/part4_ro.gif';
			showSubmenu( imgNum );
			return;
		}
		case 5: {
			document.images.menu5.src = 'images/menu/part5_ro.gif';
			showSubmenu( imgNum );
			return;
		}
		case 6: {
			document.images.menu6.src = 'images/menu/part6_ro.gif';
			showSubmenu( imgNum );
			return;
		}
	}
}

function revertMenu( imgNum ) {
	switch( imgNum ) {
		case 1: {
			document.images.menu1.src = 'images/menu/part1.gif';
			return;
		}
		case 2: {
			document.images.menu2.src = 'images/menu/part2.gif';
			return;
		}
		case 3: {
			document.images.menu3.src = 'images/menu/part3.gif';
			return;
		}
		case 4: {
			document.images.menu4.src = 'images/menu/part4.gif';
			return;
		}
		case 5: {
			document.images.menu5.src = 'images/menu/part5.gif';
			return;
		}
		case 6: {
			document.images.menu6.src = 'images/menu/part6.gif';
			return;
		}
	}
}

function changeSubmenu( submenuNum ) {
	document.images[ "submenu" + submenuNum ].src = 'images/menu/sub_menu/' + ("submenu" + submenuNum + "_ro") + '.gif';
}

function revertSubmenu( submenuNum ) {
	document.images[ "submenu" + submenuNum ].src = 'images/menu/sub_menu/' + ("submenu" + submenuNum ) + '.gif';
}

function showSubmenu( menuNum ) {
	var menu = "m" + menuNum;
	var submenu = "submenu" + menuNum;
	var left = parseInt( document.documentElement.offsetWidth );
	var top = 100;

	var version = navigator.appVersion;
	if( version.toLowerCase().indexOf("win") == -1 ) {
		return;
	}

	if( document.all[menu].menu == "true" ) {

		left = (left-750)/2 + 100;
		if( parseInt( document.documentElement.offsetWidth ) < 750 ) {
			left = 100;
		}
		document.all[submenu].style.left = left;

		for( i = 0; i < menuNum; i++ ) top = (34 * i) + 98;
		document.all[submenu].style.top = top;

		document.all[submenu].style.display = "block";
	} 
}

function hideSubmenu( menuNum ) {
	document.all[ "submenu" + menuNum ].style.display = "none";
}

function closeMenus( menuNum ) {
	for( i = 1; i <= 6; i++ ) {
		if( document.all[ "m" + i ].menu == "true" ) {
			document.all["submenu" + i].style.display = "none";
		}
	}
}

function goBack() {
	oldURL = document.referrer;

	if( oldURL == "http://www.fourwaysdentalsurgery.co.uk/" ) {

		alert(oldURL);
		window.location = "/";
	}
	else if( oldURL.search("fourwaysdentalsurgery.co.uk") > 0 ) {
		history.back();
	} 
	else {
		window.location = "/";
	}
}