objRolloverImage = function (strKey)
{
	this.onImg = new Image();
	this.onImg.src = strBtnSrc + strKey + "_on" + strBtnExt;
	
	this.offImg = new Image();
	this.offImg.src = strBtnSrc + strKey + strBtnExt;
}

rollover = function (eltImg, nPos, bOn)
{
	eltImg.src = (bOn) ? aButtons[nPos].onImg.src : aButtons[nPos].offImg.src;
}

var i;
var strBtnSrc = "/education/images/button_";
var strBtnExt = ".png";
var aBtnNames;
var aButtons;