function switchMenu(obj) {
	var el = document.getElementById(obj);
	if ( el.style.display != "none" ) {
		el.style.display = 'none';
	}
	else {
		el.style.display = '';
	}
}
/* cycle images */
var imgArray = new Array("b2","c2","c1","b1","a1","a2","a3","b3","c3");
var len = imgArray.length
var imgDir = "";
var num = 0;

for (i = 0; i < len; i++) {

    imageObj1 = imgArray[i] + "";
    temp = eval(imageObj1 + " = new Image()");
    temp.src = imgDir + imageObj1 + ".jpg";

}

function StartCycle() {

    eval("document."+imgArray[num]+".src = "+imgArray[num]+".src");
    num = num + 1;

    if (num < len) {
        setTimeout("StartCycle()", 1000);
        }
}