//button image names
var buttons = new Array("bt_about", "bt_careers", "bt_children", "bt_school", "bt_printed");
var topLevelButtons = buttons.length;

var imgs = new Array;
for(i=0;i<topLevelButtons;i++){
	//preload images
	imgs[i] = new Array;
	imgs[i][0] = new Image; 
	imgs[i][0].src = '/assets/images/topnav/home_off.gif';
	imgs[i][1] = new Image;
	imgs[i][1].src = '/assets/images/menu/'+buttons[i]+'_2.gif';
	imgs[i][2] = new Image;
	imgs[i][2].src = '/assets/images/menu/'+buttons[i]+'_1.gif';
}

var imgObj;
function over(imgNum) {

	//reset all images
	menuClosingFunction();

	//image object
	if(ns4) { imgObj = document.layers["navlayer"].document.images["b"+imgNum]; }
	else { imgObj = document.images["b"+imgNum]; }

	//change image
	imgObj.src = imgs[imgNum][1].src;

	//find position of image
	xPos = getRealLeft(imgObj);
	yPos = getRealTop(imgObj) + 2 + imgObj.height;

	//activate menu with returned co-ordinates
	if(menuReadyState) { 
		activateMenu(imgNum,xPos,yPos); 
		//alert(xPos);
		//alert(yPos);
	}
}

function menuClosingFunction() {
	//reset all images
	for(i=0; i < topLevelButtons; i++){
		if(ns4) { 
			imgObj = document.layers["navlayer"].document.images["b"+i]; 
		}
		else { 
			imgObj = document.images["b"+i]; 
		}
		imgObj.src = imgs[i][0].src;
	}
}