I wasn't too sure where to post this. Please feel free to put it in whatever forum it belongs

Anyway,
I have been having ongoing difficulties with proper placement of javascripts in vb to make everything happy.
More specifically,
what could cause parts of css to be ignored after adding a javascript to the header insert?
My hover has ceased working apon adding javascripts to the header insert.
What are some errors that could cause this?
-Littlebit