关于asp:RadioButton的问题,请帮忙

<asp:RadioButton ID="rbOriginal" runat="server" Text="原创:" GroupName="filecom" />
<asp:RadioButton ID="rbReproduced" runat="server" Text="转载:" GroupName="filecom"  />
<asp:TextBox ID="txtReproduced" runat="server" Height="48px" Width="352px" TextMode="MultiLine" Visible="false"> </asp:TextBox>
这是ASPX页面的表单元素

protected string reReproduced = "";
protected string txtRep = "";
protected void Page_Load(object sender, EventArgs e)
    {
reOriginal = this.rbOriginal.ClientID;
reReproduced = this.rbReproduced.ClientID;
}

<script type="text/javascript" language="javascript">
    function radiobuttonCheck()
    {
        var radiOriginal=document.getElementById("reOriginal").value;
        var radReproduced=document.getElementById("reReproduced").value;
        var txtRep=document.getElementById("txtRep").value;
        if(radReproduced.checked==true)
        {
        txtRep.display=none;
        }