1. A method for providing information, for display on a client, related to text displayed by a pre-existing application program running on the client, the method comprising: providing, in electronic data format, criteria for electronic analysis of the text being displayed on the client in order to identify at least one part of the text as first information being associated with second information that is in an information source accessible by the client via the internet, the criteria being sufficient, when applied to the text, for the analysis to identify the first information without any need for prior human designation of text comprising the first information, and wherein (i) the criteria comprise comparing parts of the text being displayed to elements in at least one list comprising textual elements, and, if a part of the text being displayed includes at least one of the elements, such part is considered first information, and (ii) the second information depends on textual content of the first information; providing to the client a computer code device for the pre-existing application program displaying the text, wherein the computer code device is stored on a computer readable medium and made accessible via the internet to the client, and the computer code device is configured (1) to provide within the pre-existing application program an input device configured to enable entry of an execute command at the client, (2) upon receipt of the execute command, to cause retrieval of the second information, and (3) after such retrieval, to cause display of the second information in a window on the client; and using the computer code device to cause, in response to receipt of the execute command, delivery via the internet to the client of the second information for display in a window on the client.