if(navigator.appVersion.charAt(0)>=3){
var imgAry=new Array();

for(i=0;i<8;i++){
imgAry[i]=new Image();
}

imgAry[0].src="./images/navi-home.gif";
imgAry[1].src="./images/navi-home_over.gif";
imgAry[2].src="./images/navi-access.gif";
imgAry[3].src="./images/navi-access_over.gif";
imgAry[4].src="./images/navi-exroom.gif";
imgAry[5].src="./images/navi-exroom_over.gif";
imgAry[6].src="./images/navi-reading.gif";
imgAry[7].src="./images/navi-reading_over.gif";
}

function changeImg(dim,cnt){
if(navigator.appVersion.charAt(0)>=3){
document.images[dim].src=imgAry[cnt].src;
};
};