Custom control inside an update panel doesn't fire click event in ASP.NET project ask question

i have custom control which is button and is configured to enable or disable for certain user groups with key value, i have over ridden the render event of custom control and checking weather user has access to this button and den render it.

i have grid and this custom control button which are placed inside the update panel and click event of this is not firing at all

but if i attach a JavaScript function to on-click attribute of that button, it does full post back, but i want partial post back, how to achieve it? below is my custom control button

<pre>public class RBACButton : System.Web.UI.WebControls.Button
{

    private string _rbacKey;

    public string RbacKey
    {
        get { return _rbacKey; }
        set { _rbacKey = value; }
    }

    /// <summary> 
    /// Render this control to the output parameter specified.
    /// </summary>
    /// <param name="output"> The HTML writer to write out to </param>
    protected override void Render(HtmlTextWriter output)
    {
        //TODO the commented block below has to be uncommented
        bool hasAccess = RBACManager.Instance.HasAccess(_rbacKey);
        if(hasAccess)
            base.Render(output);
    }

}

}