Prime Number Application

gistfile1.txt

  Dim numValue As Integer = 0
  Dim maxNumValue As Integer = 0

    Private Sub btnPrime_Click(sender As Object, e As EventArgs) Handles btnPrime.Click
        lstPrimeNumbers.Items.Clear()
        numValue += 1
        maxNumValue = txtMaxNumber.Text
            For Me.numValue = 0 To maxNumValue
                isNumberPrime()
            Next
    End Sub

    Private Sub isNumberPrime()
        Dim isPrime As Boolean = False
        Dim a, c As Integer
        a = numValue
        c = 0
        For i = (a - 1) To 2 Step -1
            If a Mod i = 0 Then
                c += 1
            End If
        Next i
        If c = 0 Then
            isPrime = True
        End If
        If isPrime = True Then
            lstPrimeNumbers.Items.Add(numValue)
        End If
    End Sub
End Class