var imgCatA = new Array();
if (document.images) {
	for (var i=0; i<20; i++) {
		imgCatA[i] = new Image;
		imgCatA[i].src = eval('"images/btn_" + eval(i) + ".gif"');
	}
}
function depressImgA(num) {
	if (document.images) {
		var imgName = "btn_" + eval(num);
		var imgLoc = num + 1;
		eval('document.images["' + imgName + '"].src = imgCatA["' + imgLoc + '"].src');
	}
}
function releaseImgA(num) {
	if (document.images) {
		var imgName = "btn_" + eval(num);
		eval('document.images["' + imgName + '"].src = imgCatA["' + num + '"].src');
	}
}