>>Hi Andrus,
>>
>>One method is to use the .Net Framework System.Windows.Forms.MessageBox() method.
>
>I need to do long calculations between messages like
>
>? 'Starting log calculation'
>DoLongCalculation()
>? 'Ending log calculation'
>
>I dont understand how to use messagebox for this.

I would create a custom form to handle this. I would reccomend using the BackgroundWorker to do the long calculation.