[Zope] Request data and form data

Calling a DTML method/document with argument is easy, like: <A HREF="say_hello?who=<dtml-id>">Say hello</A> This uses URL link to call a DTML document/method. But if I use form submit to call, like <FORM ACTION="say_hello?who=<dtml-id>"> <INPUT TYPE='TEXT' NAME="name" SIZE=20> <INPUT TYPE='submit'> </FORM> then the "say_hello" document will respond with "Name Error: who not found". It seems that using form submit cannot transmit request data like "?who=...". Then how can I supply argument to the responding DTML document, in addition to the form data?