protected override void CreateChildControls()
        {
            InternalHiddenField l = new InternalHiddenField();
            l.ID = this.ControlID + "_textboxInternal";
            this.Controls.Add(l);

            KeyPressEventExtender ext = new KeyPressEventExtender();
            ext.ControlID = this.ControlID;
            ext.TargetControlID = this.ControlID + "_textboxInternal";
            this.Controls.Add(ext);

            base.CreateChildControls();
        }
        protected override void CreateChildControls()
        {
            InternalHiddenField l = new InternalHiddenField();

            l.ID = this.ControlID + "_textboxInternal";
            this.Controls.Add(l);

            KeyPressEventExtender ext = new KeyPressEventExtender();

            ext.ControlID       = this.ControlID;
            ext.TargetControlID = this.ControlID + "_textboxInternal";
            this.Controls.Add(ext);

            base.CreateChildControls();
        }