JS-DUC (Java Script - Dynamic Update Composer). Helps create JavaScript-include files for dynamic updating webpages. This will let you change multiple web pages by altering one file only. Freeware by Hollmn Digital.
Instructions:
To use JS-DUC simply copy/paste your source code into the upper text pane, and press ">> CODE IT <<". The output will be shown in the lower pane. Click "Save" and save the file. Now copy the implementation text and insert it in your HTML file. Done!