run-time error handlers...

Hey Guys...I need to get some info about error handlers. I need to write error handler that focuses on invalid numeric values, numeric overflow or underflow, and putting text chars as opposed to number values...any suggestions?

Could you be a little more specific in how you are adding this information to your database? Like are you using a textbox, data combo box, etc.?

For me the easiest way to control the data input is to use either a data combo box populated with information from another table (e.g. for the field "STATE" I would have a DBCombo linked to a table with a list of states) or to use the KeyPress routine in a text box. Example: a text box where you only want the user to input numeric data to a maximum of 10 digits looks like this:

Private Sub txtCode_KeyPress (KeyAscii As Integer)

If KeyAscii < Asc("0") Or KeyAscii > Asc ("9") Then
KeyAscii = 0
End If

If Len(txtCode.text) = 10 and KeyAscii <> vbKeyBack Then
KeyAscii = 0
End if

Exit sub

Here is the code that I want to use the ascii for:
Private Sub cmdEvaluate_Click()
On Error GoTo error_handler
If mnuPayment.Checked = True Then
txtPayment = FormatCurrency(Pmt(CDbl(txtInterestRate), _
CDbl(txtPeriods), CDbl(txtPresentValue), (txtFutureValue), 0), 2)
ElseIf mnuPresentValue.Checked = True Then
txtPresentValue = FormatCurrency(PV(CDbl(txtInterestRate), _
CDbl(txtPeriods), CDbl(txtPayment), (txtFutureValue), 0), 2)
ElseIf mnuFutureValue.Checked = True Then
txtFutureValue = FormatCurrency(FV(CDbl(txtInterestRate), _
CDbl(txtPeriods), CDbl(txtPayment), (txtPresentValue), 0), 2)
Else
MsgBox "Must check Calculation option"
End If
Exit Sub
error_handler:
MsgBox "Cannot Calculate using the given values", vbCritical
End Sub

My questions is: Can I put the ascii routine within this private sub or do I need to make its own sub (Reason Why I ask is that I got the Error handler within it...I want to keep it within one area)?

Thanxs for the help :) :)