if you are trying to integrate dockable panel support in your existing script, you might have noticed some example code in the “The Window menu and ScriptUI Panels folder” section of the After Effects CS3 Scripting Guide. however, if you use it, you’ll get an “Unable to execute script at line n. show is undefined” error when the script is launched from the Window menu. unfortunately, the show() method is not available for the Panel object. as such, you need to check that your script is using a Window object (which is used when the script is launched from the File > Scripts > Run Script File menu command, or other non-ScriptUI Panels folder way), e.g.,

if (myToolsPanel instanceof Window)
    myToolsPanel.show();

my recent CS3 script updates use this type of conditional check to support dockable and non-dockable UIs in the same script.