I searched the http://wiki.servoy.com/display/public/DOCS/Web+Client+compatibility+overview
It says nothing about event.getModifiers().
But it seems not to work with (for example) a Shift-click on a button:
In the globals.onAction(event) my first statement is if(event.getModifiers()==17), but
it only works with the smartclient.
Any suggestions about this ?