To enhance convenience for a user when using a printer equipped with multiple paper feed ports having different loadable paper size ranges to the paper feed ports, to print paper of user-defined paper size.

A printer driver 304, when a "front end paper cassette" is input in a paper feed method input field ic22 when displaying a paper size pull down menu pm23, judges whether or not each user-defined paper size stored in a memory 252 is within a loadable paper range to the front end paper cassette 102, when it is judged that the user-defined paper size is within the range, sets to ON a paper size display flag included in user-defined paper information stored in the memory 252 and when it is judged that the user-defined paper size is not within the range, sets to OFF the paper size display flag. Then, the user-defined paper information whose paper size display flag is ON is extracted to display a user-defined paper name.