>Guys...
>
>I just want to ask several things :

It is considered more appropriate to write your two non-related questions in two separate messages.

>1. different using
> return "" with return(0) and return .f.

RETURN returns a value back to the calling function.

For instance:

? CircleArea(5)

FUNCTION CircleArea(radius)
  return Radius * Radius * pi()
ENDFUNC

RETURN 0 will return the value 0, and RETURN .F. will return the value .F. These values are different.

>2. What's _tally meant ? what its use for ?

_tally returns the number of records processed by the latest command. Several commands that process records will update this.

Example:

select * from MyTable where ... into cursor Temp
if _tally = 0
  MessageBox("There are no records. Please change the selection criteria.")
else
  report form ...
endif

HTH, Hilmar.