1. A method for selectively altering the display of page elements, said method comprising: a. receiving, at a client, a page dynamically generated by a plurality of code fragments executing on a server, comprising an executable function and a plurality of elements, each element generated by a code fragment of the plurality of code fragments and designated by an identifier; b. displaying, by the client in a web browser, the received page; c. executing, by the client in response to at least one user input, the executable function, the executable function sending a request to the server, the request initiating execution of a first code fragment of the plurality of code fragments to generate an updated element; d. receiving, by the client from the server, a response comprising the updated element and a modification list comprising an identifier identifying a first element in the page also generated by execution of the first code fragment, wherein a partial page regenerator executing on the server generates the modification list responsive to using a map of correspondences to identify elements in the page received by the client and updated elements generated by the same code fragments; and e. displaying, by the client in the web browser, an updated page incorporating the updated element by replacing the first element in the page with the updated element according to the modification list.