Multiple Ranges in Slider

Hi guys ,
I'm working with the SLIDER plugin ,i WANT TO HAVE THE ABILITY TO get
multiple Ranges in the Slider
the code should look something like this . but it doen't work it seems
it just works with one range
does any one has any Idea ,
thanks
$("#PrimaryRules_slider").slider({
range: true,
min: 0,
max: 500,
values: [ [75,300] , [310,400] ] ,
slide: function(event, ui) {
}
});