ImageButton in ASP.NET

Hello Experts,

I have repeater on my page but there is no CS file. I am using custom control.

In my repeter, there is one Imagebutton -

<asp:ImageButton ID="imgbtnDelete" runat="server" CommandName="Delete" OnClientClick="javascript:return confirm('Are you sure you want to delete this ?')"/>

Now I want to set this confirm text 'Are you sure you want to delete this ?' for globalization purpose but I don't have CS file. Can anyone tell me how I can do this?

Thanx in advance. 

In ASPX side you can write this:

<script runat="server">
    
    #region Page Load Method
    /// <summary>
    /// Page Load
    /// </summary>
    /// <param name="sender">The source of the event.</param>
    /// <param name="e">The <see cref="System.EventArgs"/> instance containing the event data.</param>
    protected void Page_Load(object sender, EventArgs e)
    {
     }
    #endregion

</script>