On error do yourErrorroutine with ...

code line 1
code line 2 && which causes the error
code line 3

Function YourErrorRoutine
Lparameter ...
... some message to the user
Do Case
Case ... && Retry the code which causes the error (line 2) 
  Retry
Case ... && Ingore the error and go on with thenext line (line 3)
  Return
Case ... && Stop processing
  Cancel && this stops all processing. look out with this.
EndCase