I need to assign code to a button, that when clicked on, validates an ISBN code, and displays a message that it is either Valid or Invalid. I basically need help transforming code used in a console application that will now be used in a windows form application, so no more writeline stuff, now message boxes.
Here is the code I need help with:
Select Case ISBN.Length
Case 10
Dim x As Integer = 0
noCheck = ISBN.Substring(0, ISBN.Length - 1)
x = checkISBN10(ISBN, noCheck)
If x = 11 Then
noCheck += "0"
ElseIf x = 10 Then
noCheck += "X"
Else
noCheck += x.ToString
End If
If (ISBN <> noCheck) Then
System.Console.WriteLine("Invalid ISBN - Check digit is " & x)
End If
Case Else
System.Console.WriteLine("Invalid ISBN length")
End Select
Private Function checkISBN10( _
ByVal ISBN As String, ByVal noCheck As String) As Integer
Dim x As Integer = 0
If ISBN.Length = 10 Then
x = 10 * Integer.Parse(noCheck.Chars(0))
x += 9 * Integer.Parse(noCheck.Chars(1))
x += 8 * Integer.Parse(noCheck.Chars(2))
x += 7 * Integer.Parse(noCheck.Chars(3))
x += 6 * Integer.Parse(noCheck.Chars(4))
x += 5 * Integer.Parse(noCheck.Chars(5))
x += 4 * Integer.Parse(noCheck.Chars(6))
x += 3 * Integer.Parse(noCheck.Chars(7))
x += 2 * Integer.Parse(noCheck.Chars(8))
x = 11 - (x Mod 11)
End If
Return x
End Function
Also, how do I make a connection between a button and textbox. In other words, if a button is clicked on, how do I assign it to read that certain textbox where the information was entered?
Unsolved 
