function random(){
var rmduri = new Array("http://www.studio-ryokucha.com/koisora/","http://www.studio-ryokucha.com/koisora/","http://windmill.suki.jp/","http://windmill.suki.jp/","http://www.feng.jp/","http://www.feng.jp/");
var rmdimg = new Array("http://www.studio-ryokucha.com/koisora/banner/koisora500_1.jpg","http://www.studio-ryokucha.com/koisora/banner/koisora500_ser.jpg","http://windmill.suki.gr.jp/product/denikeri/banner/iro_ban_710_120_01.jpg","http://windmill.suki.gr.jp/product/denikeri/banner/iro_ban_710_120_03.jpg","http://hoshikaka.jp/banner/710x100_1.jpg","http://hoshikaka.jp/banner/710x100_4.jpg");
var imgwidth = new Array("500","500","710","710","710","710");
var imgheight = new Array("100","100","120","120","100","100");
var rmd = Math.floor(Math.random()*rmdimg.length);
document.write("<a target=\"_blank\" href=\"" + rmduri[rmd] + "\">");
document.write("<img src=\"" + rmdimg[rmd] + "\" WIDTH=\"" + imgwidth[rmd] + "\" HEIGHT=\"" + imgheight[rmd] + "\">");
document.write("</a>");
}