A first extension program and a second extension program operate on a web browser. The first extension program displays a content managed by a document management server in a display area, and when the content has been dragged outside the display area, writes information of the dragged content in a bridge data storage unit. The second extension program generates a drag object including the content information written in the bridge data storage unit and monitors whether the drag object has been dropped outside the web browser. When the drag object is dropped outside the web browser, the second extension program executes download processing by using the content information included in the drag object.