In order to prevent these browsers from attempting to initialize menus that they can't use, a special template conditional is used.
$show['popups']
By surrounding all vBMenu controls and popups in a conditional that checks the value of $show['popups'], Javascript errors can be avoided, and alternative HTML can be shown to browsers that can't use popups.
For example:
<if condition="$show['popups']"> <!-- content here is for browsers that are able to use the vBMenu system --> <else /> <!-- content here is shown to browsers that are unable to use vBMenu popups --> </if>