img = new Array();
// 画像のアドレス(数字はジャンプ先のアドレスと対応)
img[0] = "<div id='gallary'><a href='ex_def_01.html'><img src='images/top_gallary_def_01.jpg' /></a></div>";
img[1] = "<div id='gallary'><a href='ex_def_02.html'><img src='images/top_gallary_def_02.jpg' /></a></div>";
img[2] = "<div id='gallary'><a href='ex_hana_01.html'><img src='images/top_gallary_hana_01.jpg' /></a></div>";
img[3] = "<div id='gallary'><a href='ex_baobab_01.html'><img src='images/top_gallary_baobab_01.jpg' /></a></div>";
img[4] = "<div id='gallary'><a href='ex_kaze_01.html'><img src='images/top_gallary_kaze_01.jpg' /></a></div>";
n = Math.floor(Math.random()*5);
document.write(img[n]);