function SwapImage(ImgName, ImgSrc) {
document.images[ImgName].src=ImgSrc;
}

PreImg=new Array();
for(i=1; i<=8; i++) {
PreImg[i]=new Image();
}
PreImg[1].src="/common/image/nav01.gif";
PreImg[2].src="/common/image/nav02.gif";
PreImg[3].src="/common/image/nav03.gif";
PreImg[4].src="/common/image/nav04.gif";
PreImg[5].src="/common/image/nav05.gif";