URL, coding question

[Zeitgeist]

Is there a way to supply as an argument a subject to a new pm?

https://elliquiy.com/forums/index.php?action=pm;sa=send;u=4190

I experimented with adding to the above such things as:

;su=Hello
;subject=Hello

etc.

Thoughts? Ideas? I've nosing around SMF too for anything but haven't found anything useful yet.

Thanks