How does one impliment a locking mechanism in Oracle 7.3 using VB 6 as the
front end? In one of the modules I am developing a transaction requires to
lock a few records of a table for updation later on, so that these records
are not changed by other users.

The SELECT * FROM table_name FOR UPDATE statement works, but when some other
user attempts to update the same set of records Oracle goes into a deadlock.
Is there any way to control a lock timeout in Oracle, which will generate
an error when a user attempts to obtain a lock on a record that is already
locked by some other user. This will help the application to show an error
message to the user who fails to get the required record lock.