My Zen has vanished. I want to calculate some images and have them displayed. I tried some simple experiments with external methods. ImageClock(self) computes the bytes for a Gif image of the current time. UniqueId(self) returns a unique identifier. ChartClock is defined thusly def ChartClock(self): return self.REQUEST['ChartClock'] when this is displayed I see the first image, but not the second. <dtml-var standard_html_header> <p>This works <img src=ImageClock?_,<dtml-var UniqueId> ></p> <dtml-call "REQUEST.set('ChartClock',ImageClock(_))"> <p>This doesn't <img src=ChartClock?_,<dtml-var UniqueId> ></p> <dtml-var standard_html_footer> Firstly why don't I get an error with too many arguments. Secondly why/how do these two processes differ. The reason for the <dtml-var UniqueId> is to make each view of the clock different. -- Robin Becker