Current function within a Stored Procedure.

Here's a synopsis of the problem I'm trying to solve: I have a table (table_a) with two datetime columns (start_time, end_time). At the beginning of a stored procedure, I want to insert a row into table_a setting start_time to the current datetime. The stored procedure then executes a bunch of other statements that take up to several hours to execute. At the end of the procedure, I want to update table_a end_time to the current datetime (different than the start datetime). Because the Informix 'current' function in a stored procedure returns only one value, I'm having trouble registering the two different times. Do you know of any work-arounds. Thanks for your help. Pete