Hi
Try this code:

Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Address = "$B$1" Then
Range("A1").Value = Range("A1").Value + Range("B1").Value
End If
End Sub

you have to write this code to "Work sheet module"


"Flying_Dutcman" wrote:

I need to replace the value in A1 with the entered value in B1. eg, A1=20;
B1=20 now I type 30 into B1 and A1=50. Is this at all posibble? Please help?