//Ëæ»úÊý²úÉúÆ÷ function rand(r) { var seed = Math.random(); return Math.ceil(seed * r); } function showad(n) { document.write(code[n]); } var sumRate = 0; var count = 0; var rate = new Array(count); var code = new Array(count); var randnum = rand ( sumRate ); var begin = 1; var end = 1; var i = 0; while(i= begin && randnum < end){ showad(i); break; } i++; }