>In a form execute a process every 10 seconds, I would like to display a log in some kind of notes field for every occurence of the loop. What is the best control to use for that and how would I go to insert a line addtionnaly to the existing content of the notes field?

Hmm... you could use System.Diagnostics.Trace class. Then write a Trace Listener that logs the trace messages wherever you want them to go.

You also might want to look at log4net which gives you tons of instrumentation options.

BOb