confirmation alert from code-behind (in If- Condition)

Hi all,

I need to put an alert from code-behind on certain conditions.

Please help me out -

My aspx page and aspx.cs code are as follows -


 <asp:GridView ID="grdEmployeeDetails" runat="server" AutoGenerateColumns="false" Width="100%">
                            <Columns>
                                <asp:TemplateField>
                                    <HeaderTemplate>
                                        <asp:CheckBox ID="chkHeader" runat="server" />
                                    </HeaderTemplate>
                                    <ItemTemplate>
                                        <asp:CheckBox ID="chkRow" runat="server" />
                                    </ItemTemplate>
                                </asp:TemplateField>                                
                                <asp:BoundField DataField="Employee Name" HeaderText="Name"  />
                                <asp:BoundField DataField="Salary" HeaderText="Salary" " />
                                <asp:BoundField DataField="Dept" HeaderText="Department" />
                                <asp:BoundField DataField="Desig" HeaderText="Designation />
        </Columns>
                            <HeaderStyle Width="60px" Height="50px" />
                            <RowStyle Width="200px" />
                        </asp:GridView>

        <div>
                        <asp:Button ID="btnYes" runat="server" Text="yes"
                            OnClick="btnYes_Click"  />
                        &nbsp;
                        <asp:Button ID="btnNot" runat="server"  Text="No"
                           OnClick="btnNo_Click" />
                    </div>
-------------
aspx.cs -
btnYes_ClickEvent -
{
  Int32 totalCount = grdGetAsset.Rows.Cast<GridViewRow>().Count(r => ((CheckBox)r.FindControl("chkRow")).Checked);
if (totalCount > 0)
{
     string message = "Do you want to Submit?";
     System.Text.StringBuilder sb = new System.Text.StringBuilder();
     sb.Append("return confirm('");
     sb.Append(message);
     sb.Append("');");
     ClientScript.RegisterOnSubmitStatement(this.GetType(), "alert", sb.ToString());
 
 // here if user clicks "Yes" , then proceed further. Else No
 // How to check which button user have clicked ??
}