Private Sub cmd_Click()
Dim a As Variant, c As Variant
a = Val(txt.Text)
c = 2
Do While c * c <= a
If a Mod c = 0 Then
lbl.Caption = "Aval Nist" + vbCr + "be " + CStr(c) + " bakhshpazir ast."
Exit Do
End If
c = c + 1
Loop
If c * c > a Then lbl.Caption = "Aval Hast"
End Sub