Prime Number or not using function in VB.NET.

PROPERTIES:

Button1
Text	Prime

CODEING:

Public Class Form1
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        If IsNumeric(TextBox1.Text) Then
            Dim ans As Integer = prime(Val(TextBox1.Text))
            If ans = 0 Then
                MsgBox(Val(TextBox1.Text) & " is Prime Number")
            Else
                MsgBox(Val(TextBox1.Text) & " is Not Prime Number")
            End If
        Else
            MsgBox("Enter Numeric Value")
        End If
    End Sub
    Function prime(ByVal num As Integer) As Integer
        Dim i As Integer = 2
        Dim k As Integer = 0
        While i <= num / 2 And k = 0
            If num Mod i = 0 Then
                k = 1
            Else
                i += 1
            End If
        End While
        Return k
    End Function
End Class

DESIGNING: