A webpage print server transmits script to a client terminal that has run a bookmarklet, and the client terminal that has run the script transmits an HTML of a webpage under display by a web browser to the webpage print server. In the case where the webpage print server was unable to acquire the external files in accordance with an external file reference command contained in this HTML, the webpage print server transmits script that causes acquisition of external files to the client device, and the webpage print server acquires the external files from the client device. The webpage print server then generates printing data based on the acquired external files and the aforementioned HTML.