function replaceImage(RightImageObj, NewImageUrl){
var NewImageUrl = 'img/' + NewImageUrl;
document.getElementById(RightImageObj).src = NewImageUrl;
}

function navRollovers(target,state) {
	if (state == 'over') {
	replaceImage(target, (target + '_o.gif'));
	} else {
	replaceImage(target, (target + '.gif'));
	}
}