adding text box values

i am writing a golf score program and i have 18 text boxes. i also have a text box that will calculate the total of all of the 18 other text boxes. what would be the best way to add these text boxes? i have already written code to only except numbers 1 thru 8 for each text box.

i started with some code like this:

Code:

---

TextBoxTotal.Text = CInt(TextBoxHole1.Text) + CInt(TextBoxHole2.Text) + CInt(TextBoxHole3.Text)

---

but if there is no value in one of the text boxes i get an error:
Conversion from string "" to type 'Integer' is not valid.

so i am guessing i need to check for empty strings and then ignore them

any suggestions?

here's my solution. it works with empty text + invalid entries:

vb Code:

Public Class Form1
 
    Dim textboxes() As TextBox
 
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        textboxes = Me.Controls.OfType(Of TextBox).Where(Function(tb) tb.Name.StartsWith("TextBoxHole")).ToArray
        For Each tb As TextBox In textboxes
            AddHandler tb.TextChanged, AddressOf tb_TextChanged
        Next
    End Sub
 
    Private Sub tb_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs)
        Dim sum As Decimal = 0D
        For Each tb As TextBox In textboxes
            Dim value As Decimal = 0D
            Decimal.TryParse(tb.Text, value)
            sum += value
        Next
        TextBoxTotal.Text = sum.ToString
    End Sub
 
End Class