登录验证码

 function showLoginImg() {
     document.write("<img src='http://ptverifypaipai.paipai.com/getimage?" + Math.random() + "' align='absmiddle' id='loginImg'>　<a href='#' onclick='refreshLoginImg()'>刷新</a>");
 }
 function refreshLoginImg() {
     document.getElementById("loginImg").src = "http://ptverifypaipai.paipai.com/getimage?" + Math.random();
 }