Not able to get service order errors

Hi,

My requirement is to terminate service order from saving if there are duplicate and convert the warning to error message, I wrote a code in the order_save badi implementation.

I tried using CRM_MESSAGES_Search, display and collect, I am getting the loghandle from crm_order_read (with requested objects Messages) but not able to retrieve the messages from all this function module, its retrieving nothing, I tried passing header guid, item guid and handle

its not returning anything. can any one guide me, how to get all the service order errors saved in Web ui.

thanks

dinesh