[rules-users] class ont found error using BRMS

Hi I am new in drools. Whenever I import a .drl file to make a package in BRMS,then make model to load a class then upload it. After that I try to save and validate configuration.. I find error.. class not found. Why does model upload only jar file instead of class file ? how to do this.. I think i am donig some worng to import. Whats wrong... ?? Plz Help Thanks in adavance Rahul Upadhyay