Someone help me out here? I can set the max length of a textbox to 8 but when I do something it can still input a number greater than 8 into the textbox. For example, if I push a button it can put 8+ letters or numbers in it. The reason I want this is because I have this code for a DateTimePicker ValueChanged event:

firsthoursbox.Text = Convert.ToString(firstendbox.Value - firststartbox.Value);

And.. When I first click it. It will give something like 00:59:59.8750000

It's kind of annoying.. Someone help me out here? Thanks.