extending xsl with javascript

Hi,

I am interested using JavaScript with my xsl templates to control branching logic but do not have a clue where to start. For example one ability I'd like to create is to be able to access command line parameters to a page:

myXML2HTMLpage.xml?mode=List


I have come across a couple of web sites but they all make my head spin (it is not pretty!) and I'm not sure if I'm ready to embrace a third party library (especially since hugs are no longer allowed in US schools...?)

Can anyone suggest a good, introductory, place to start? hopefully with examples...


Thanks in advance for your help!

Kind Regards, 
April