hi, everybody! I have a question, if i have one box and i want to calculate the size of this box which command that i can use? as we know that if we want to calculate the size of box, it is: AxBxC. Could u tell me?

You mean the volume of a box? You can use the MASSPROP command - see:
http://www.cadforum.cz/cadforum_en/qaID.asp?tip=3972

Ok, that nice thanks for ur helping.