>i want to know how to have the number of grids on a form.
>if there is one grid, i want to export to excel only fields that are on the grid. how to do it ?

COMPLETELY UNTESTED. Maybe it will give you a starting point

loGrid = ""
lnGridCount = 0
FOR i = 1 TO thisform.controlcount
   IF thisform.controls[i].class = "grid"  && or your gridclass name
      loGrid = thisform.controls[i]
      lnGridCount = lnGridCount + 1
   ENDIF
ENDFOR

DO CASE
   CASE lnGridCount = 0   && no grids
   CASE lnGridCount > 1   && too many grids
   CASE lnGridCount = 1
      SELECT loGrid.RecordSource
      COPY TO < filename > TYPE XLS
ENDCASE

Assuming this works on simple forms there are plenty of tweaks which may be needed. You will need to tweak it if you have more than one class of grids. You will need to tweak it if you use pageframes and the grid is on one of the pages.

Good luck.