Both multiselects are created with the following one-liner. Optgroup support is built in out of the box:
$(function(){ $("select").multiselect(); });
Option 1 Option 2 Option 3 Option 4 Option 5 Option 6 Option 7 Option 8 Option 9 Option 10 Option 11 Option 12
Click on an optgroup's heading to toggle the checked state of the entire group.
Option 1 Option 2 Option 3 Option 4 Option 5 Option 6 Option 7