ASP.NET Button is not firing an event

<%@ Page Language="C#" AutoEventWireup="true" MasterPageFile="~/EuroFlexMaster.master" Title="Remarks Master" Theme="Flex" CodeFile="Remarks_Master.aspx.cs" Inherits="GRNMaster_Remarks_Master" %>

 <div id="Dia Master">
        <fieldset style="width: 90%; height: 95%;">
            <legend style="width: 130px; text-align: center; color: #9900ff; font-size: 14px;">New Remarks</legend>
            <table border="0" style="height: 90%; width: 111%">
                <tr style="height: 25px">
                    <td colspan="5"></td>
                </tr>
                <tr>
                    <td style="width: 25%; height: 92px;"></td>
                    <td style="width: 9%; height: 92px;">
                        <label id="lblRemarks">Remarks</label>
                    </td>
                    <td style="height: 92px; width: 25%;">
                        <asp:TextBox runat="server" ID="txtRemarks" TextMode="MultiLine" MaxLength="240" Width="100%" Height="100%"></asp:TextBox><br />
                    </td>
                    <td style="width: 12%; height: 92px;">   
                             <asp:RequiredFieldValidator ID="ReqRemarks" runat="server" ForeColor="Red" ControlToValidate="txtRemarks" ErrorMessage="Enter Remarks" SetFocusOnError="true" Display="Dynamic" Text="*"></asp:RequiredFieldValidator>
                    </td>
                    <td style="width: 217px; height: 92px;"></td>
                </tr>
                <tr>
                    <td style="height: 25px; width: 25%;"></td>
                    <td style="height: 25px; width: 9%;"></td>
                    <td valign="top" align="right" style="height: 25px; width: 25%;"></td>
                    <td valign="top" align="right" style="height: 25px; width: 12%;"> </td>
                    <td style="height: 25px; width: 217px;"></td>
                </tr>
                <tr>
                    <td style="height: 25px; width: 25%;"> </td>
                    <td style="height: 25px; width: 9%;"></td>
                    <td valign="top" align="right" style="height: 25px; width: 25%;">
                        <center>
                            <asp:Button runat="server" ID="btnRemarksView" Text="View All" OnClick="btnRemarksView_Click" CausesValidation="false" />
                            <span> </span>
                            <asp:Button runat="server" ID="btnSave" Text="Save" OnClick="btnSave_Click1"  CausesValidation="true"/>
                            <span> </span>
                            <asp:Button runat="server" ID="Clear" Text="Clear" OnClick="Clear_Click" CausesValidation="false" />
                            <span> </span>
                        </center>
                    </td>
 </tr>

            </table>
        </fieldset>
    </div>

using System;
using System.Collections.Generic;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class GRNMaster_Remarks_Master : System.Web.UI.Page
{
protected void Clear_Click(object sender, EventArgs e)
    {
        txtRemarks.Text = "";
        remarkView.Visible = false;
    }
  protected void btnSave_Click1(object sender, EventArgs e)
    {
        MyDBmgr = new MySqlDBMgr();            //Declaring New Instance of DataBase Object

        string cmd = string.Empty;             //String Declaration for DataBase Query
        string cmdInsert = string.Empty;       //String Declaration for DataBase Query
        cmdInsert = "insert into euroflexworkflow.remarksmaster(RemarkName) Values('" + txtRemarks.Text + "')";
        MyDBmgr.RunSqlCommand(cmdInsert, true); //Passing Query to method which Executes query
        FlexUtilities.ShowAlert(this, " Record Inserted Successfully");
        txtRemarks.Text = "";
    }
  protected void btnRemarksView_Click(object sender, EventArgs e)
    {
        Rebind();
    }

    protected void Rebind()
    {
        MyDBmgr = new MySqlDBMgr();   //Declaring New Instance of DataBase Object
        DataSet RemarkDS = new DataSet();
        RemarkDS = MyDBmgr.RunProcedure("getremarksdetails");
        remarkView.DataSource = RemarkDS.Tables[0].DefaultView;
        remarkView.DataBind();
        remarkView.Visible = true;
        Session["myDataset"] = RemarkDS;
        trGrdCount.Visible = true;
    }
}