Hi:
I'm not exactly sure what you mean by "subclass" but if your new template inherits from the parent of "ivb", then it will have the changed (or child) DOC_HEAD event. If your new template inherits from a parent of tagsets.html4, then you will have the original DOC_HEAD event.
A template can only have 1 parent. So when you use PARENT=IVB, if IVB has PARENT=TAGSETS.HTML4, all inheritance between IVB and HTML4 is resolved before IVB becomes the new parent.
One thing you might consider is having the DOC_HEAD event in each template trigger a new event, which will only write the JAVASCRIPT you want...something like this:
[pre]
define tagset ivb;
parent=tagsets.html4;
define event doc_head;
..... whatever you want here or just copy original ....
...... but add your own "trigger" statement ....
trigger ivb_js;
end;
define event ivb_js;
....your "ivb" javascript stuff is here...
end;
[/pre]
and then your new "subclass" tagset template:
[pre]
define tagset subclass;
parent=tagsets.ivb;
define event ivb_js;
** what is here overrides what is in tagsets.ivb;
trigger sub_js;
end;
define event sub_js;
... put your subclass javascript here ...
end;
[/pre]
Or, alternately, just have the "subclass" tagset template inherit from tagsets.html4 instead of from tagsets.ivb:
[pre]
define tagset subclass;
parent=tagsets.html4;
define event doc_head;
..... whatever you want here or just copy original ....
...... but add your own "trigger" statement ....
trigger sub_js;
end;
define event sub_js;
....your "subclass" javascript stuff is here...
end;
[/pre]
I haven't tested it out, since I don't know enough JavaScript to be useful, but an approach like this might do what you want, depending on what you mean by "subclass".
cynthia