Write code in VBA for customer data entry and generate bill

 Here's some example code in VBA that demonstrates how to create a basic data entry form for customer information and generate a bill based on that information:

'Form module

Private Sub cmdSave_Click()

    'Collect customer information from form

    Dim customerName As String

    customerName = Me.txtName.Value

    

    Dim customerAddress As String

    customerAddress = Me.txtAddress.Value

    

    Dim customerPhone As String

    customerPhone = Me.txtPhone.Value

    

    Dim customerEmail As String

    customerEmail = Me.txtEmail.Value

    

    'Collect product information

    Dim productName As String

    productName = Me.txtProductName.Value

    

    Dim productPrice As Double

    productPrice = Me.txtProductPrice.Value

    

    Dim quantity As Integer

    quantity = Me.txtQuantity.Value

    

    'Calculate total cost

    Dim totalCost As Double

    totalCost = productPrice * quantity

    

    'Generate bill

    Dim bill As String

    bill = "Invoice for customer " & customerName & vbNewLine & vbNewLine & _

    "Contact Information:" & vbNewLine & _

    "Address: " & customerAddress & vbNewLine & _

    "Phone: " & customerPhone & vbNewLine & _

    "Email: " & customerEmail & vbNewLine & vbNewLine & _

    "Order Information:" & vbNewLine & _

    "Product Name: " & productName & vbNewLine & _

    "Quantity: " & quantity & vbNewLine & _

    "Total Cost: " & totalCost & vbNewLine

    'display bill

    MsgBox bill

End Sub

This code creates a form with text boxes for customer name, address, phone number, email and product information, like product name, quantity, product price, and then calculates the total cost of purchase. The generated bill will be shown on the screen in the form of a message box.

Keep in mind that this is just an example and you can customize it to your needs and also include more fields as per requirement.

It would also be a good idea to include a way to save the bill to a file or database, depending on your application's needs.