Button event in GridView not responding. C#

Question

I have a problem with my buttons in the grid view. It is not responding to my Response.Redirect("secondHistory.aspx") and my Console.WriteLine("hih"). Here is the HTML code

<asp:GridView runat="server" AutoGenerateColumns="false" ID="GridView1" OnSelectedIndexChanged="GridView1_SelectedIndexChanged" OnRowCommand="GridView_RowCommand" Width="1027px">
    <Columns>
        <asp:BoundField DataField="ExcelID" HeaderText="Excel ID" />
        <asp:BoundField DataField="excelName" HeaderText="Excel Name" />
        <asp:BoundField DataField="excelDescription" HeaderText="Excel Description" />
        <asp:BoundField DataField="date / time" HeaderText="Date / Time" />
        <asp:BoundField DataField="empID" HeaderText="Employee ID" />
        <asp:BoundField DataField="empName" HeaderText="Employee Name" />
        <asp:BoundField DataField="engID" HeaderText="Engineer ID" />
        <asp:BoundField DataField="engName" HeaderText="Engineer Name" />
        <asp:BoundField DataField="firstApproval" HeaderText="First Approval(Engineer)" />
        <asp:TemplateField HeaderText="Second Approval (Manager)">
            <ItemTemplate>
                <asp:Button ID="acceptBtn" runat="server" 
                    CommandName="Accept"
                    CommandArgument="<%# ((GridViewRow) Container).RowIndex %>"
                    Text="Accept" />
            </ItemTemplate>
        </asp:TemplateField>

    </Columns>
</asp:GridView>

and here is the backend code of the button.

 protected void GridView_RowCommand(object sender, GridViewCommandEventArgs e)
    {
        if (e.CommandName == "Accept")
        {
            // Retrieve the row index stored in the 
            // CommandArgument property.
            int index = Convert.ToInt32(e.CommandArgument);

            // Retrieve the row that contains the button 
            // from the Rows collection.
            GridViewRow row = GridView1.Rows[index];

            // Add code here to add the item to the shopping cart.
            Console.WriteLine("hih");
            Response.Redirect("secondHistory.aspx");
        }
    }

Here is the code to populate the table if its necessary.

protected void GridView1_SelectedIndexChanged(object sender, EventArgs e)
    {
        DataTable dt = new DataTable();
        dt.Columns.Add("ExcelID", typeof(int));
        dt.Columns.Add("excelName", typeof(string));
        dt.Columns.Add("excelDescription", typeof(string));
        dt.Columns.Add("date / time", typeof(string));
        dt.Columns.Add("empID", typeof(int));
        dt.Columns.Add("empName", typeof(string));
        dt.Columns.Add("engID", typeof(int));
        dt.Columns.Add("engName", typeof(string));
        dt.Columns.Add("firstApproval", typeof(string));
        dt.Columns.Add("secondApproval", typeof(string));

        for(int i = 0; i < textfiles.Length; i++)
        {
            textList.Add(File.ReadAllText(textfiles[i]));

        }

        string[] textArray = textList.ToArray();

        for (int i = 0; i < excelfiles.Length; i++)
        {
            dt.Rows.Add(i, excelfiles[i], textArray[i] , File.GetCreationTime(textfiles[i]), 837482, "*empName*", 917378, "*engName*", "Approved");
        }


        GridView1.DataSource = dt;
        GridView1.DataBind();
    }

Please help thanks!