i had a display.java;i compiled it,and founded a display.jar files.then i deleted the display.java and display.class;i had an other Usedisplay.java . i use the display.class's object in the Usedisplay. both display.jar and Usedisplay.java have a path.but i compile the Usedisplay.java ,is wrong!show the "package display does not exit"," import display.*" please help me ,i think to use the class from .jar files! i m sorry ,my english level is not well!