I see a lot of online code using this structure, most notably in references to Ajax in Action, in particular; things like: While I understand how call works, what I can't figure out is why it is needed in this situation.
The code in my subject line seems to me to be exactly the same in effect as:
It would make sense to me if it were:
Am I missing something here?
Trying to remember the exact code since I do not have it in front of me, but I think it is actually needed in that situation since this.onerror can be set in a different scope since it can be a reference to an outside method. It has been awhile since I looked at Dave's Ajax stuff.