[JQuery] jquery 確認帳號是否重復

      $('#account').blur(function(){

         $.get( "chk_account.php", {account: this.value},

            function(data){  // data的值：chk_account.php 會 echo true or false

               if(data) {

                  finishAjax("account_msg", escape("<span style='color:#FF0000'>帳號可以使用</span>"));

                  return true; // 另一個問題，如 (註1)

               }

               else {

                  finishAjax("account_msg", escape("<span style='color:#FF0000'>帳號已註冊</span>"));

                  return false;

               }

            }

         )

      });

   function finishAjax(id, data) {

      $('#'+id).html(unescape(data));

      $('#'+id).fadeIn();

   }

   $(document).ready(function(){

      $('#account').blur(function(){

         if(this.value.length == 0)

            finishAjax("account_msg", escape("請輸入帳號"));

         else {

            $.get( "chk_account.php", {account: this.value},

                   function(data){

                      if(data) {

                         finishAjax("account_msg", escape("帳號可以使用"));

                         return true;   // 這裡的 return 好像沒有效果

                      }

                      else {

                         finishAjax("account_msg", escape("帳號已註冊過"));

                         return false;  // 這裡的 return 好像沒有效果

                      }

                   }

                 );

         }

         return false;

      });

   });