JSP新手提问,在提交前的判断,如果空值,页面把原来输入的值都清了

Question

修改3个地方 
  <form   onsubmit="return   adduserst()"     action=""   name="form1"   method="post"   enctype="multipart/form-data">       
//   增加   onsubmit 
<input   name="Submit"   type="submit"               class="submit"               value="添加">       //   去掉   onclick                 <script               type="text/javascript">                                       function               adduserst(){       
                                                if(document.form1.paneid.value               ==               ""){       
                                                                alert("方格号不能为空");       
                                                                doucment.form1.paneid.focus();       
                                                                return               false;       
                                                }       
                                                if(document.form1.userid.value               ==               ""){       
                                                                alert("用户名不能为空");       
                                                                doucment.form1.userid.focus();       
                                                                return               false;       
                                                } 
return   true;               //   增加这一句 
                                }       
                </script>