*In the Init of the form FrmA

procedure frma.init
Public pActiveB, myotherform  && I'll not use pActiveB
pActivB = .f.
endproc

*In the Form FrmA (command button)

procedure mybuttom.click
If type("myotherform.name")<>"C"
   Do form .\ecran\FrmB.scx name myotherform
Else
   myotherform.Caption= "Allo"
   myotherform.Show()
   activate window (myotherform.name)
Endif
endproc