simple data binding is not synchronized

Question

Hi, sorry for the newbie question. I really hope someone can tell me what I am wrong. I just want to try simple data binding using following simple code. hourText is a TextBox, I bound its Text property with variable hour. When reach the point "after bind", the TextBox's Text has the value "100", but after execute "hour=200", the Text doesn't change. int hour; hour = 100; hourText.DataBindings.Add("Text", hour, null); // after bind hour = 200; Could anyone tell me what I am wrong? thanks a lot Fanso