After Update Error

[Dreamcatcher]

Probably an easy solution but i'm a bit of a newbie and just need a little code help.

Basically, i have a SFrm_Unders_Overs which controls a finance fund for each salesperson. The form allows you to enter a Fund_Adjustment figure and i just want the Fund_Value control to auto update the total fund amount after each adjustment.

I.e Adjustment1 = -$5 Fund_Value = -$5, Adjustment2 = $30 Fund_Value = £25 etc

I've currently entered After Update code against Adjustment_Value -
Private Sub Adjustment_Value_AfterUpdate()
If Me!Adjustment_Value <> 0 Then
Me!Value = Me!Value + Me!Adjustment_Value
End If
End Sub

Currently this is just updating the Fund_Value with the latest Adjustment_Value amount and not accumulating the adjustments for a running total in the Fund_Value.

Any help would be appreciated.

Regards