How to show and hide textbox in gridview on link button click - asp.net

Question

I have gridview,which has approve and reject button.When click on reject button i need to show textbox for comments else no.after enetering comments i have save it in data base.How to do this can any one help me
here is my code:
<asp:GridView ID="GridView1" runat="server" AllowPaging="True" AutoGenerateColumns="False" BackColor="White"
BorderColor="#CCCCCC" BorderStyle="None" BorderWidth="1px" CellPadding="4" ForeColor="Black"
GridLines="Horizontal" OnRowDataBound="GridView1_RowDataBound">
<Columns>
<asp:TemplateField HeaderText="Industrial Zone">
<ItemTemplate>
<asp:Label runat="server" ID="lblindzone" Text='<%# Eval("indzone") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="District">
<ItemTemplate>
<asp:Label runat="server" ID="lbldstr" Text='<%# Eval("dstr")%>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Industrial Area">
<ItemTemplate>
<asp:Label runat="server" ID="lblnmindar" Text='<%# Eval("nmindar")%>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Plot Number">
<ItemTemplate>
<asp:Label runat="server" ID="lblplno" Text='<%# Eval("plno")%>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Approve/Reject">
<ItemTemplate>
<asp:LinkButton ID="lnkApproved" runat="server" Text="Approve" OnClick="lnkApproved_Click"><img src="images/approve.png" style="width:20px;height:20px; margin:5px" title="Approve"/></asp:LinkButton>
<asp:LinkButton ID="lnkReject" runat="server" Text="Reject" OnClick="lnkReject_Click" OnClientClick="return showandhide(this)"><img src="images/reject.png" style="width:16px;height:16px; margin:5px" title="Reject"/></asp:LinkButton>
<asp:LinkButton ID="lnkviewdetails" runat="server" Text="View Details" OnClick="lnkviewdetails_Click"><img src="images/viewdetails.png" style="width:20px;height:20px; margin:5px" title="Details" /></asp:LinkButton>
<asp:TextBox ID="txtcomment" runat="server" style="display:none"></asp:TextBox>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Status">
<ItemTemplate>
<asp:Label runat="server" ID="lblstatus" Text='<%# Eval("status")%>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>

Answer 1

I am assuming you are doing it with only C# and no Javascript. to view or hide a specific textbox you should trigger a RowCommand Event of GridView:
protected void GridView1_RowCommand(object sender, GridViewCommandEventArgs e)
{
if (e.CommandName == "viewhide")
{
GridViewRow gvr = (GridViewRow)(((LinkButton)e.CommandSource).NamingContainer);
TextBox tbComments = ((TextBox)gvr.FindControl("txtcomment"));
tbComments.Visible = true;
}
}
And this would be your ASPX Codebehind
<asp:LinkButton ID="lnkReject" runat="server" Text="Reject" OnClick="lnkReject_Click" CommandName="viewhide" OnClientClick="return showandhide(this)"><img src="images/reject.png" style="width:16px;height:16px; margin:5px" title="Reject"/></asp:LinkButton>
EDIT: Now You've changed the tag from C# to VB.NET which is not good. because i consumed all my time writing a c# code!