IMAGE FORMING SYSTEM CHANGING PRINTING DIRECTION EVERY PRINTING FILE AND METHOD THEREOF

An image forming device changing a printing direction by each printing file and a controlling method thereof are provided to change the printing direction of each printing file by outputting a document according to the printing direction determined according to a flag value, which determines the printing direction, and changing the flag value whenever the printing file is output. An interface part(130) receives a printing request of a file from at least one networked terminal(200), and a printing direction register(111) stores a direction flag value for printing a document. A controller(110) outputs the received file according to the printing direction corresponding to the value stored in the printing direction register and changes the flag value of the printing direction register. The controller outputs the document in a normal direction when the flag value is zero, outputs the document in an inverse direction when the flag value is one, and changes the flag value from zero to one, or from one to zero after one file is printed. An operation panel(160) activates or inactivates an alternative outputting function.