How to write code behind for hyper link tag

Question

I am trying to use hyperlink tag and I need to write code behind for that , which shows and hide place holder when I click the link 

 

please help  

Thanks  

 

<asp:HyperLink id="linkbtn" runat="server" Text="Forgot Password?"  OnClick="link1_Click"></asp:HyperLink>
                       <asp:PlaceHolder ID="typeEmail" runat="server" Visible="false">
                       <asp:TextBox ID="textbox1" Visible="true" runat="server" AutoComplete="off">
                       </asp:TextBox>
                       </asp:PlaceHolder>





protected void link1_Click(object sender, EventArgs e)
   {
        typeEmail.Visible = true;
       textbox1.Visible = true;
        }