Calculate field tool is assigning the FIRST VALUE to all the records!!!

[AshakaThakore]

I am trying to calculate field
i m using vb type of expression

in the codeblock i have written this code
Dim getCVAL
If (Diameter>10) Then
  getCVAL="1234"
else
  getCVAL="4567"
End if

in the expression, i have written getCVAL

Calculate field tool is assigning the FIRST VALUE to all the records!!!

now what is wrong with this code,
please help thanks

[MarcinGasior]

If "Diameter" is a field containing values, it should be in [] brackets:

Dim getCVAL
If [Diameter] > 10 Then
  getCVAL = "1234"
Else
  getCVAL = "4567"
End If

[AshakaThakore]

yes its a field... thanks a lot