SESSION ID ?

Hi, I have many applications that connects to the Informix Engine quite often. I would like to track the session id of a specific application that updates a specific table ( say employee. ). This sid will be used to capture information from syssessions table. ( hostname and proecss id ) The problem i have is "how to identify the session id, when the table is being updated" There are quite a few commands available ( Eg. onstat, or query the sysmaster table ) to get the session id information as a whole. But I would like to know, can we map the session id as part of a procedure or trigger ? By this way, I can use the sid in the trigger to capture other information from the syssessions Thanks for the help...