Remove messages from WebIc 4.0

Hi All

I need to remove certain messages from the message area in the Web Ic.

I have tried the following code but it does not seem to work

lv_msgsrv->collect_messages( iv_message_type = IF_GENIL_MESSAGE_CONTAINER=>MT_ALL

iv_delete_read_messages = abap_true ).

Does anyone know how to do this

Thanks