// HpbImgFind: Imageオブジェクトを探します
//
function	HpbImgFind(doc,imgName) {
	for( var i=0;i<doc.layers.length;i++ ) {
		var	img = doc.layers[i].document.images[imgName];
		if( !img ) {
			img = HpbImgFind(doc.layers[i],imgName);
		}
		if( img ) {
			return	img;
		}
	}
	return	null;
}
// HpbImgSwap: 画像を入れ換えます
//
function	HpbImgSwap( imgName,imgSrc ) {
	var	appVer=parseInt( navigator.appVersion );
	var	isNC=( document.layers && (appVer>=4) );	// Netscape Navigator 4.0 or later
	var	isIE=( document.all    && (appVer>=4) );	// Internet Explorer 4.0 or later
	if( document.getElementById ) {
		isOK = true;
	}
	if( isNC || isIE || isOK ) {
		if( document.images ) {
			var	img = document.images[imgName];
			if( !img ) {
				img = HpbImgFind( document,imgName );
			}
			if( img ) {
				img.src = imgSrc;
			}
		}
	}
}