try

   Select Case Me!Fruit
       Case "Banana"
           Me!Fruit = Null
       Case "Papaya"
           Me!Fruit = "Apple"
   End Select

hth

I don't think you can change the value of the field in a report: in any
case I don't think you'd want to. Set the Controlsource of the textbox to
a custom function that you are about to write:

 = RenameFruit([Fruit])

Then put this sort of thing in the Report module:

 ' rename the fruit
 ' note the use of variants so it does not
 ' fall over with the use Nulls
 '
 Public Function RenameFruit(SomeFruit As Variant) _
     As Variant

   If IsNull(SomeFruit) Then
     RenameFruit = Null

   Else
     Select Case SomeFruit
     ' etc as suggested by Tina
       Case "banana" : RenameFruit = Null
       Case "papaya" : RenameFruit = "Apple"
       Case Else : RenameFruit = "Yum, yum, something new!"
     End Select
   End If
 End Function

Hope that helps

Tim F