How can I do something similar to the following C code in VB 6?
#ifdef _DEBUG_
// do things
#else
// do other things
#end if
Cody has told you about conditional compilation. I'd like to add that if you want different behaviour when debugging on the IDE (e.g. turn off your own error handling so that the IDE traps errors) you don't need conditional compilation. You can detect the IDE at runtime like this.
On Error Resume Next
Debug.Print 1/0
If Err=0 then
'Compiled Binary
Else
'in the IDE
End if
This works because Debug.Print is omitted in the compiled EXE.