.net 中用JS 检测表单是否为空

首先是检测表单的JS代码：

  CheckForm()
{
    var i=0;
    var txtTilles=document.getElementById("txtTitle"+i);
    do
    {

        if(txtTilles.value=="")
        {
            errMessageLable("请输入标题");

            return false;
        }

        txtTilles=document.getElementById("txtTitle"+(++i));
    }
    while(txtTilles)
    return true;
}

JS 错误信息提示

errMessageLable(strMessage)
{
    var lblErrMes=document.getElementById("lblErrMes");
    lblErrMes.style.color="red";
    lblErrMes.innerText=strMessage;

}
function ClearErrMessageLable()
{
    var lblErrMes=document.getElementById("lblErrMes");
    lblErrMes.innerText="";

}

aspx页面里为BUTTON 添加 OnClientClick事件:

完整代码如下

<title>无标题页</title>
    <style type="text/css">
        .style1
        {
            width: 293px;
        }
        .style2
        {
            width: 94px;
        }
        .style3
        {
            width: 153px;
        }
    </style>
<script language="javascript" type="text/javascript">
// <!CDATA[

function btnAddOther_onclick()
{
  var divVideo=document.getElementById("videoFileUPControl");
      var newinput=document.createElement("input");
      newinput.type="file";
      divVideo.appendChild(newinput);

}
function  CheckForm()
{
    var i=0;
    var txtTilles=document.getElementById("txtTitle"+i);
    do
    {

        if(txtTilles.value=="")
        {
            errMessageLable("请输入标题");

            return false;
        }

        txtTilles=document.getElementById("txtTitle"+(++i));
    }
    while(txtTilles)

}

function errMessageLable(strMessage)
{
    var lblErrMes=document.getElementById("lblErrMes");
    lblErrMes.style.color="red";
    lblErrMes.innerText=strMessage;

}
function ClearErrMessageLable(strMessage)
{
    var lblErrMes=document.getElementById("lblErrMes");
    lblErrMes.innerText="";

}
// ]]>
</script>
</head>
<body>
    <form id="form1" runat="server" enctype="multipart/form-data">
    <div>

         <table style="width:100%;">
             <tr>
                 <td class="style2">
                     <asp:Label ID="Label1" runat="server" Text="上传视频"></asp:Label>
                 </td>
                 <td class="style3">
                     标题：</td>
                 <td class="style1">
                     <asp:Label ID="Label2" runat="server" Text="文件："></asp:Label>
                 </td>
                 <td>

                     <asp:Label ID="lblErrMes" runat="server" ForeColor="Red"></asp:Label>
                 </td>
             </tr>
             <tr>
                 <td class="style2" valign="top">
                      </td>
                 <td class="style3">

                     <asp:Panel ID="titlePanl" runat="server" >
                         <asp:TextBox ID="txtTitle0" runat="server"></asp:TextBox>
                     </asp:Panel>
                    </td>

                 <td class="style1">

                     <asp:Panel ID="videoFileUPControl" runat="server" >
                         <asp:FileUpload ID="FileUpload1" runat="server" />
                     </asp:Panel>
                    </td>

                 <td valign="top">
                   
                     <asp:Button ID="btnAddOther" runat="server" Text="添加视频"
                         onclick="btnAddOther_Click" />
                      
                     <asp:Button ID="btnSub" runat="server" onclick="btnSub_Click" Text="减少" />
                 </td>
             </tr>
             <tr>
                 <td class="style2">
                      </td>
                 <td class="style3">
                     <asp:Button ID="btnUPload" runat="server" Text="上传"  OnClientClick="if( !CheckForm()){setTimeout(ClearErrMessageLable ,6000);return false}" onclick="btnUPload_Click" />
                 </td>
                 <td class="style1">
                      <asp:Button ID="Button1" runat="server" Text="重置"
                         onclick="Button1_Click" />
                 </td>
                 <td>
                      </td>
             </tr>
         </table>

         </div>
    </form>

</body>
</html>