[Zope] Tree + post variables??

[vanroose wim]

Zopees,

            I have a simple, stupid question.

            I have a page that has a variable in the URL  example
"localhost:9673/TreePage?story_id=199093459087"

            When I open the tree, which is generated with an sql method
thru  branches_expr,   by clicking on the plus sign the story_id
variable is not anymore accessible.
Because the url of the + sign does not contain the story_id variable.

                I know, I still    use the zope 1.3 but I didn't Have
time yet to upgrade.....

            Code

<!--#with "_.namespace(obj_id=0)"-->

 <!--#tree   id=obj_id
 branches_expr="SiteStruct(param=obj_id)" nowrap=1
 single=1 -->
<!--#var name-->

<!--#if story-->
<!--#var story-->
<!--#/if-->
 <!--#/tree-->
<!--#/with-->

And the sql method is
<!--#if param-->
select sid AS obj_id,descr AS name, isleave
 from structure where pid=<!--#sqlvar param type=string-->
<!--#else-->
select sid AS obj_id,descr AS name,isleave
 from structure WHERE pid=''<!--#/if-->

The structure table is

mysql> show columns from  structure;
+---------+-------------+------+-----+---------+-------+
| Field   | Type        | Null | Key | Default | Extra |
+---------+-------------+------+-----+---------+-------+
| sid     | varchar(20) |      |     |         |       |
| descr   | varchar(30) |      |     |         |       |
| pid     | varchar(30) |      |     |         |       |
| isleave | varchar(10) | YES  |     | NULL    |       |
+---------+-------------+------+-----+---------+-------+

You can dump some values in the database with

INSERT INTO structure VALUES ('1','Een','','');
INSERT INTO structure VALUES ('2','Twee','','');
INSERT INTO structure VALUES ('3','Drie','','');
INSERT INTO structure VALUES ('4','EenEen','1','Yes');
INSERT INTO structure VALUES ('5','EenTwee','1','Yes');
INSERT INTO structure VALUES ('6','TweeEen','2','Yes');
INSERT INTO structure VALUES ('7','TweeTwee','2','Yes');
INSERT INTO structure VALUES ('8','DrieEen','3','Yes');
INSERT INTO structure VALUES ('9','DrietWee','3','Yes');