1. An image processing apparatus adapted to communicate with an external server via a network, the image processing apparatus comprising: a display; a Web browser unit configured to load Web content data containing document data described by a markup language and embedding a JavaScript or information for identifying a JavaScript and to generate screen information to be displayed by the display based on the loaded Web content data, wherein the embedded JavaScript or the JavaScript identified by the embedded information is linked to a document object model, wherein the Web content data is transmitted from the external server, and wherein the Web browser unit comprises a script interpreter configured to interpret the document data contained in the Web content data to perform script processing based on the embedded JavaScript or the JavaScript identified by the embedded information; and an executing unit configured to execute at least one of a plurality of functions of the image processing apparatus based on a command instructing execution of the one of the plurality of functions, wherein the command is included in the embedded JavaScript or the JavaScript identified by the embedded information based on which script processing is performed by the script interpreter, wherein the at least one of the plurality of functions, executed based on the command included in the embedded JavaScript or the JavaScript identified by the embedded information, is executed by calling a control API (Application Program Interface) from an event processing unit, associated with the document object model, included in the image processing apparatus, and wherein at least another of the plurality of functions of the image processing apparatus, executed based on a user interaction, is executed by calling the control API from one or more applications associated with one of scanning or copying, included in the image processing apparatus.