Originally Posted by felgall
While having a . in an id is valid such ids have problems as the dot has different meanings with respect to most of the places where ids can be used. For example the dot means a class definition when you try to reference the id from css and so the css will not be applied correctly.
It is only really when using the id as an anchor within the HTML that the dot in the id is unlikely to cause problems.
Ok. Well I changed the <div id="menubar.php"> to <div id="menubar"> and it didn't make any difference.