var ib_img = new Array ();
	for(var i=1; i<4; i++){
		pb_img[i] = pb_image();
		pb_img[i].src = "top_img/pb_button"+"i" +"b.gif";
	}

function chgimg_1(chname, imgname){
	document.images[chname].src = imgname;
}

var ib_img = new Array ();
	for(var i=1; i<4; i++){
		ib_img[i] = ib_image();
		ib_img[i].src = "icon/ib_button"+"i" +"b.gif";
	}

function chgimg_2(chname, imgname){
	document.images[chname].src = imgname;
}