How can I Plot an OLE graph in a VFP form ?

I created a chart and saved it in a General field

Later the user wants to change the way the graph is PLOTED
from Row to Column in a form just selecting an option
button of the form.

THISFORM.oGrafico is an OLE bound control of the form where I show the chart.

I think to Plot a graph in a VFP form the way is using the SetSourceData method,
but it doesnt work.

THISFORM.oGrafico.SetSourceData(THISFORM.oGrafico.ActiveSheet.Range("A1:A154"),2)

But it returns this: Member ACTIVESHEET does not evaluate to an object.

If I try this:

THISFORM.oGrafico.SetSourceData(THISFORM.oGrafico.Sheet("Plan1").Range("A1:A154"),2)

it return this: Member SHEET does not evaluate to an object.

Question:
Which is the name, or how can I get the object of the sheet from a OLE graph in a VFP form
to execute the SetSourceData method ?
Or is there another way to plot the graph

Please, I need Help....

Thanks In Advance.