ok im using

Public Function CheckText(MyText As String) As Boolean

'function returns True if text is OK else returns False

If MyText = "" Then
CheckText = False
Exit Function
End If


If Not IsNumeric(MyText) Then
CheckText = False
Exit Function
End If

'If we get to here, MyText is a number
' So set function to true

CheckText = True

End Function

then calling it and doing some calculations with

Private Sub txtsupplyfo2_Change()


If CheckText(txtsupplyfo2.Text) = True Then

'do the calculations for related datatxtmaxpo2.Text = txtsupply.Text * txtbar.Text
txtmaxpo2.Text = txt.supplyfo2.Text * txtbar.Text
txtfio2.Text = ((txttotaldump.Text * txtsupplyfo2.Text) - txtconsumption.Text) / (txttotaldump.Text - txtconsumption.Text)
Else
txtmaxpo2.Text = ""
txtfio2.Text = ""
End If

End Sub

all this works fine until I do the one above where there are 2 calculations. Also txtdepth_Change (not seen above) is used calculates txtbar.Text and txtmaxpo2.Text and txtbar_Change calculates txtdepth.Text and txtmaxpo2.text

Is the problem that I am not supposed to the same calculation from two difeerent txt box changes? Or is it that I have numerous txt boxes cross calculating the same data as other checkboxes???

Help me please.

Scott