程序标识符改错

Question

Public Class Form1
    Function gcd(ByVal m, ByVal n) As Integer
        Dim r, t As Integer
        If m < n Then t = m : m = n : n = t
        r = m Mod n
        Do While (r <> 0)
            m = n : n = r : r = m Mod n
        Loop
        gcd = n
    End Function
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim m, n As Integer
        m = Val(TextBox1.Text)
        n = Val(TextBox2.Text)
        TextBox3.Text &=  gcd (   Space(10 - Len(m,n ," )"   .
        TextBox3.Text &= vbCrLf
    End Sub
End Class