// Image オブジェクトを生成し、変数に格納
var profile_on = new Image();
var profile_off = new Image();
var env_on = new Image();
var env_off = new Image();
var tl_on = new Image();
var tl_off = new Image();
var weblog_on = new Image();
var weblog_off = new Image();
var link_on = new Image();
var link_off = new Image();


// src プロパティに画像を設定
profile_on.src = "./image/icon/profile_up.jpg";
profile_off.src = "./image/icon/profile.jpg";
env_on.src = "./image/icon/env_up.jpg";
env_off.src = "./image/icon/env.jpg";
tl_on.src = "./image/icon/tl_up.jpg";
tl_off.src = "./image/icon/tl.jpg";
weblog_on.src = "./image/icon/two-weblog_up.jpg";
weblog_off.src = "./image/icon/two-weblog.jpg";
link_on.src = "./image/icon/link_up.jpg";
link_off.src = "./image/icon/link.jpg";


// カーソルがオブジェクト上に乗った場合の処理
function rollon(targetimage) {
	if(targetimage=="profile") {
		document.images[targetimage].src = profile_on.src;
	} else if(targetimage=="env") {
		document.images[targetimage].src = env_on.src;
	} else if(targetimage=="tl") {
		document.images[targetimage].src = tl_on.src;
	} else if(targetimage=="weblog") {
		document.images[targetimage].src = weblog_on.src;
	} else if(targetimage=="link") {
		document.images[targetimage].src = link_on.src;
	}
}


// カーソルがオブジェクト上から外れた場合の処理
function rolloff(targetimage) {
	if(targetimage=="profile") {
		document.images[targetimage].src = profile_off.src;
	} else if(targetimage=="env") {
		document.images[targetimage].src = env_off.src;
	} else if(targetimage=="tl") {
		document.images[targetimage].src = tl_off.src;
	} else if(targetimage=="weblog") {
		document.images[targetimage].src = weblog_off.src;
	} else if(targetimage=="link") {
		document.images[targetimage].src = link_off.src;
	}
}