protected override void CreateChildControls()
        {
            this.Controls.Add(CreateTextBox());

            AutocompleteTextboxExtender ext = new AutocompleteTextboxExtender();

            ext.TargetControlID = this.ControlID + "_textbox";
            ext.ControlID       = this.ControlID;

            ext.DataSourceType    = DataSourceType;
            ext.FixedListItems    = FixedListItems;
            ext.DisplayTemplate   = DisplayTemplate;
            ext.ValueProperty     = ValueProperty;
            ext.AssociationSO     = AssociationSO;
            ext.AssociationMethod = AssociationMethod;
            this.Controls.Add(ext);



            base.CreateChildControls();
        }
        protected override void CreateChildControls()
        {
            this.Controls.Add(CreateTextBox());

            AutocompleteTextboxExtender ext = new AutocompleteTextboxExtender();
            ext.TargetControlID = this.ControlID + "_textbox";
            ext.ControlID = this.ControlID;

            ext.DataSourceType = DataSourceType;
            ext.FixedListItems = FixedListItems;
            ext.DisplayTemplate = DisplayTemplate;
            ext.ValueProperty = ValueProperty;
            ext.AssociationSO = AssociationSO;
            ext.AssociationMethod = AssociationMethod;
            this.Controls.Add(ext);

            

            base.CreateChildControls();
        }