var preimages;
preimages=new Array("../common/images/n_study_on.gif","../common/images/n_voice_on.gif","../common/images/n_cdrom_on.gif","../common/images/h_totop_on.gif","../common/images/h_english_on.gif","../common/images/h_sitemap_on.gif","../common/images/f_contact_on.gif","../common/images/f_policy_on.gif");

function chimg(filename,target){
	document.images[target].src=filename;
}
function preloadimg(){
	preloadimg=new Array();
	for(i=0; i < preimages.length; i++){
		preloadimg[i]=new Image();
		preloadimg[i].src=preimages[i];
	}
}