Dim firstNum As Double

Dim secondNum As Double

Dim result As Double

Private Sub cmdClear_Click()

txtFirstNum = ""

txtSecondNum = ""

txtResult = ""

End Sub

Private Sub cmdAdd_Click()

If IsNumeric(txtFirstNum.Text) Then

firstNum = CDbl(txtFirstNum.Text)

    Else

    MsgBox ("Please check first number")

    End If

If IsNumeric(txtSecondNum.Text) Then

secondNum = CDbl(txtSecondNum.Text)

    Else

    MsgBox ("Please check second number")

    End If

result = firstNum + secondNum

txtResult = CStr(result)

End Sub

Private Sub cmdExit_Click()

End

End Sub