if (document.images) { 
img_cache1 = new Image(); 
img_cache2 = new Image(); 
img_cache3 = new Image(); 
img_cache4 = new Image();
img_cache5 = new Image(); 
img_cache6 = new Image();
img_cache7 = new Image();
img_cache1.src = "./button/bu_home1.gif"; 
img_cache2.src = "./button/bu_male1.gif"; 
img_cache3.src = "./button/bu_female1.gif"; 
img_cache4.src = "./button/bu_puppy1.gif";
img_cache5.src = "./button/bu_gallery1.gif"; 
img_cache6.src = "./button/bu_link1.gif";
img_cache7.src = "zyukkai1.jpg";
} 
function setImage(img, image) { 
if (img) { 
img.src = image.src; 
} 
}