function cngImg(imgname,filename) {
		document.images[imgname].src = filename;
		return true;
}

function cngimg4lyr (lyrname,imgname,filename) {
	if ( document.layers ) {
		document.layers[lyrname].document.images[imgname].src = filename;
	} else if ( document.all ) {
		document.all[lyrname].document.images[imgname].src = filename;
	}
}