Need Help With VBA code

[New Comer]

I am New With Ms Access and want to create a little Database for shop.
Here is My Form structure Based on Table "Sales".

Label	Name
Customer Name	CustomerID(FK)(Combo Box)
Product Name	ProductID(FK)(Combo box)
Date	SalesDate(Bounded with Table 'Sales')
Quantity	Quantity(Text Box)
Unit Price	PricePerUnit(text box)
Total	TotalAmount(text box)
Paid	PaidAmount(text Box)
Remaining Amount	RemainingAmount(text Box)

Here is OnClick event code:

Private Sub SaveButton_Click()
    On Error GoTo ErrHandler
    
    ' Validate mandatory fields
    If IsNull(Me.CustomerID) Then
        MsgBox "Select a customer!", vbExclamation, "Missing Data"
        Exit Sub
    End If
    
    If IsNull(Me.ProductID) Then
        MsgBox "Select a product!", vbExclamation, "Missing Data"
        Exit Sub
    End If
    
    If Not IsNumeric(Me.Quantity) Or Me.Quantity <= 0 Then
        MsgBox "Enter valid quantity (greater than 0)!", vbExclamation, "Invalid Input"
        Exit Sub
    End If
    
    If Not IsNumeric(Me.PricePerUnit) Or Me.PricePerUnit <= 0 Then
        MsgBox "Enter valid price (greater than 0)!", vbExclamation, "Invalid Input"
        Exit Sub
    End If

    ' Calculate totals
    Me.TotalAmount = Me.Quantity * Me.PricePerUnit
    Me.RemainingAmount = Me.TotalAmount - Nz(Me.PaidAmount, 0)
    
    ' Save the record
    If Me.Dirty Then DoCmd.RunCommand acCmdSaveRecord
    
    ' Clear fields for next entry (retain CustomerID if needed)
    Me.ProductID = Null
    Me.Quantity = Null
    Me.PricePerUnit = Null
    Me.PaidAmount = Null
    Me.TotalAmount = Null
    Me.RemainingAmount = Null
    
    MsgBox "Sale saved successfully!", vbInformation, "Success"
    Exit Sub

ErrHandler:
    MsgBox "Error " & Err.Number & ": " & Err.Description, vbCritical, "Error"
    If Me.Dirty Then Me.Undo
End Sub

'======= AUTO-UPDATE CALCULATIONS =======
Private Sub Quantity_AfterUpdate()
    If IsNumeric(Me.Quantity) And IsNumeric(Me.PricePerUnit) Then
        Me.TotalAmount = Me.Quantity * Me.PricePerUnit
        Me.RemainingAmount = Me.TotalAmount - Nz(Me.PaidAmount, 0)
    End If
End Sub

Private Sub PricePerUnit_AfterUpdate()
    If IsNumeric(Me.Quantity) And IsNumeric(Me.PricePerUnit) Then
        Me.TotalAmount = Me.Quantity * Me.PricePerUnit
        Me.RemainingAmount = Me.TotalAmount - Nz(Me.PaidAmount, 0)
    End If
End Sub

Private Sub PaidAmount_AfterUpdate()
    If IsNumeric(Me.TotalAmount) Then
        Me.RemainingAmount = Me.TotalAmount - Nz(Me.PaidAmount, 0)
    End If
End Sub

ُProblem is:
The code is not able to clear the last field RemainingAmount's entries and not able to save the this field data to into the table. Data of Other Fields cleared and saved into to table successfully.
Please Help.
Thanks

[June7]

If you used a BOUND form and controls, this code would likely be unnecessary or reduced.

Why is it "not able" - error message, wrong result, nothing happens?

Calculated data such as Total and Remaining would not normally be saved to table.

You could provide db for analysis. Follow instructions at bottom of my post.

[New Comer]

Dear sir,
No error message appears. The code clears the form and saves the data except for the RemainingAmount field
ٖFile attached.

[June7]

Your forms ARE BOUND - data entered into controls is passed directly to table.

When you set controls to NULL, you are DELETING data from record.

Your form is set with DataEntry Yes - that means form opens to a new record row. You input data and that initiates creating a record.

Your SaveRecord code commits data to table then your code deletes data.

Data from BOUND form is committed to table when closing or navigating or run code.

You need to rethink what you are doing. Instead of setting controls to Null, move to new record row or close form.

Again, saving calculated data is usually unnecessary and risks data getting "out of sync".

[jojowhite]

in addition to the above advice, you also add Validation
on BeforeUpdate event of your form.

see the code on the Save button and test your form.

[New Comer]

Thank You Sir!! You make My day. I am thankful to you. I just Run the form.. every thing is fine even data stored in all fields. You are Great.

[New Comer]

in addition to the above advice, you also add Validation
on BeforeUpdate event of your form.

see the code on the Save button and test your form.

Thank You Sir!! You make My day. I am thankful to you. I just Run the form.. every thing is fine even data stored in all fields. You are Great.