The present invention relates to a technique for displaying the contents of a file on a display of a computer. Upon receiving an enlargement instruction for performing an enlarged display of a file, a computer detects whether an object included in the file is to be included in an enlarged display range of the file. When it is detected that the object is not to be included in the enlarged display range, the enlarged display range is automatically changed, whereby a user can understand which part of the file the enlarged display range corresponds to without performing a complicated operation.