Help No Responce When Click On Approve Button

[diya.]

i try to approve documents
code is

        protected void GrdFileApprove_RowCommand(object sender, GridViewCommandEventArgs e)
        {
 
            if (e.CommandName == "_Approve")
            {
                //using (SqlConnection con = DataAccess.GetConnected())
                using (SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["mydms"].ConnectionString))
                {
                    try
                    {
                        int rowindex = Convert.ToInt32(e.CommandArgument);
                        GridViewRow row = (GridViewRow)((Control)e.CommandSource).NamingContainer;
                        LinkButton Prove_Button = (LinkButton)row.FindControl("BtnApprove");
                        SqlCommand cmd = new SqlCommand("spinsertapprove", con);
                        cmd.CommandType = CommandType.StoredProcedure;
                        cmd.CommandType = CommandType.StoredProcedure;
                        cmd.Parameters.Add(new SqlParameter("@UserID", UserID));
                        cmd.Parameters.Add(new SqlParameter("@DocID", DocID));
                        cmd.Parameters.Add(new SqlParameter("@ApproveType", ApproveType.ToString()));
                        int result = cmd.ExecuteNonQuery();
                        if (result != 0)
                        {
                            GrdFileApprove.DataBind();
                        }
                    }
 
                    catch
                    {
                        apfi.Text = "Not Approve";
 
 
 
                    }
                    finally
                    {
                        con.Close();
                    }
                }
            }
 
 
            else if (e.CommandName == "_Reject")
            {
                using (SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["mydms"].ConnectionString))
                {
                    try
                    {
                        int rowindex = Convert.ToInt32(e.CommandArgument);
                        GridViewRow row = (GridViewRow)((Control)e.CommandSource).NamingContainer;
                        LinkButton Prove_Button = (LinkButton)row.FindControl("Button1");
                        SqlCommand cmd = new SqlCommand("sprejectapprove", con);
                        cmd.CommandType = CommandType.StoredProcedure;
                        int result = cmd.ExecuteNonQuery();
                        if (result != 0)
                        {
                            GrdFileApprove.DataBind();
                        }
                    }
 
                    catch
                    {
                        apfi.Text = "Rejct";
                    }
                    finally
                    {
                        con.Close();
                    }
                }
            }
            }

query of approve adn reject

ALTER procedure [dbo].[sprejectapprove]
@UserID int,
@DocID int,
@ApproveType nvarchar(50)
as
Insert into Approval(UserID,DocID,ApproveType)
values(@UserID,@DocID,@ApproveType)
 
Reject
 
ALTER procedure [dbo].[spinsertapprove]
@UserID int,
@DocID int,
@ApproveType nvarchar(50)
as
Insert into Approval(UserID,DocID,ApproveType)
values(@UserID,@DocID,@ApproveType)

grdiview

<center><div class="vpb_main_wrapper2" top=20 align="center" style="left: inherit"/><br clear="all"/>
        <div>
            <asp:ScriptManager ID="ScriptManager1" runat="server"/>
            <asp:UpdatePanel runat="server" ID="UPanle"
                ondatabinding="UPanle_DataBinding_Click">
                <ContentTemplate>
              <asp:GridView ID="GrdFileApprove" runat="server" AutoGenerateColumns="false"
                    onrowcommand="GrdFileApprove_RowCommand"
    onselectedindexchanged="GrdFileApprove_SelectedIndexChanged">
                  <Columns>
                      <asp:TemplateField HeaderText="S no">
                          <ItemTemplate>
                              <%# Container.DataItemIndex+1 %>
                              <asp:HiddenField runat="server" ID="HdnFileID" Value='<%# Eval("DocID") %>' />
                          </ItemTemplate>
                      </asp:TemplateField>
                      <asp:BoundField DataField="DocID" HeaderText="DocumentID"  />
                      <asp:BoundField DataField="DocName" HeaderText="DocName"  />
                      <asp:BoundField DataField="Uploadfile" HeaderText="File Name" />
                      <asp:BoundField DataField="DocType" HeaderText="Document" />
                      <asp:BoundField DataField="DepType" HeaderText="Department" />
                      <asp:TemplateField HeaderText="S no">
                          <ItemTemplate>
                              <asp:Button runat="server" Id="BtnApprove" CommandName="_Approve"
                                    CommandArgument='<%# Eval("DocID") %>' Text="Aprrove" />
                              <asp:Button runat="server" Id="Button1" CommandName="_Reject"
                                    CommandArgument='<%# Eval("DocID") %>' Text="Reject" />
                          </ItemTemplate>
                      </asp:TemplateField>
                  </Columns>
              </asp:GridView>
          </ContentTemplate>
           
           
            </asp:UpdatePanel>
   
    </div>
        <asp:Label ID="apfi" runat="server" Text="Label"></asp:Label>
 
    </center>
    </div>

when i click on approve or reject button it cannot further proceed and event not show me any error..

where is the probelm

@mahi
@mahen
@Don
@yoursks
@Redvirus