Custom Button in Popup is frozen

Hi All
I created a Popup where i want to add custom button. But after adding the buttons they are coming frozen. Please find my code i wrote in the push button event EH_ONNEXT2. Is there any thing wrong with code ?

if lr_popup_cust is not bound.

data: ls_button type crmt_thtmlb_button,

lt_button type crmt_thtmlb_button_t.

ls_button-id = 'DISP'.

ls_button-text = 'Display'.

ls_button-on_client_click = 'DISP'.

ls_button-on_select = 'DISP'.

ls_button-enabled = abap_true.

ls_button-type = cl_thtmlb_util=>gc_button_icon.

append ls_button to lt_button.

clear ls_button.

ls_button-id = 'BACK'.

ls_button-text = 'Back'.

ls_button-on_client_click = 'BACK'.

ls_button-on_select = 'BACK'.

ls_button-enabled = abap_true.

ls_button-type = cl_thtmlb_util=>gc_button_icon.

append ls_button to lt_button.

clear ls_button.

ls_button-id = 'CANCEL'.

ls_button-text = 'Cancel'.

ls_button-on_client_click = 'CANCEL'.

ls_button-on_select = 'CANCEL'.

ls_button-enabled = abap_true.

ls_button-type = cl_thtmlb_util=>gc_button_icon.

append ls_button to lt_button.

clear ls_button.

comp_controller->window_manager->create_popup_2_confirm( exporting iv_title = 'Custom Pup Up'

iv_text = 'Display Address ?'

iv_btncombination = if_bsp_wd_window_manager=>co_btncomb_custom

iv_custombuttons = lt_button

receiving rv_result = lr_popup_cust ).

lr_popup_cust->set_on_close_event( iv_event_name = 'CONFIRM_CLOSE_CUST'

iv_view = me ).

endif.

lr_popup_cust->open( ).