[Zope] newbie question: parameter passing for ZSQL Object

[zope]

Hi.

With some values that I got from a formular, I wan't to do some calculation 
stuff, and insert the calculated values into a database.

My Z SQL method'insertItem' looks like

Arguments: param1, param2, param3, param4

INSERT INTO plan
(field1, field2, field3, field4)
VALUES
(<dtml-var param1>, <dtml-var param2>, <dtml-var param3>, <dtml-var param4>)


(parameters should be integer values)

Can anybody tell me how I can call this method and pass parameters from my 
DTML method?

With <dtml-call insertItem>, Zope gives me following error message:

Zope has encountered an error while publishing this resource.
Error Type: Bad Request
Error Value: ['param1', 'param2', 'param3', 'param4']

I was checking then "ZSQL Methods User's Guide" but, they don't  give an 
example :-(

Please help. Any idea?

Thanks, Marc.