//rollovers for the navigation buttons

window.onload = initialiseRollOver;

function initialiseRollOver() {
	for (var i=0; i<document.images.length; i++) {
		if (document.images[i].parentNode.tagName == "A") {
			setupRollOver(document.images[i]);
		}
	}
}


function setupRollOver(thisButton) {
	thisButton.outImage = new Image();
	thisButton.outImage.src = thisButton.src;
	thisButton.onmouseout = rollOut;

	thisButton.overImage = new Image();
	thisButton.overImage.src = "images/" + thisButton.id + "_off.gif";
	thisButton.onmouseover = rollOver;
}


function rollOver() {
	this.src = this.overImage.src;
}


function rollOut() {
	this.src = this.outImage.src;
}