Child Behaviour

Patient: Hi, My son is 4 and half years. He is in KG2. Teachers and myself are concern about his behaviour. he cannot focus and easily destructed in the class and anyware else. if you ask him to keep quiet or listen he promise and to do it gain but after 2minutes he star doing the same thing. when he take him out some times he runs fast and he is not aware of his surroundings like traffic etc. i am really in stressed even now i myself stop arguing with my wife on any issue so that home environment also to be calm. Plus he gave hard time on eating also, he really give us hard time. education wise as per teacher response he is very good and sharp but try to finish the tast quickly so he can move to the other tast.please help me ….what to do to change his behaviour?????Already Tried:time out for 5 to 10minutes. some time i start crying so he feels i am not happy with his behaviour….