JQuery :: Setting Up Multiple Handles In Range Slider

I need to use jQuery range slider for setting up limits for multiple ranges which are interdependent, something that is similar to slider that we use for hard disk space allocation during OS installation but mine is a web applcation and the data necessary would be fetched from DB. I've tried the following code but I couldn't get two ranges. Only two handles are active.

$(function() {
$( "#slider-range" ).slider({
range: true,
min: 0,
max: 1000,
values: [ 75, 300, ],
slide: function( event, ui ) {
$( "#amount" ).val( "$" + ui.values[ 0 ] + " - $" + ui.values[ 1 ] );
}});
$( "#amount" ).val( "$" + $( "#slider-range" ).slider( "values", 0 ) +
" - $" + $( "#slider-range" ).slider( "values", 1 ) );
});
and
<div class="demo"><p>
<label for="amount">Price range:</label>
<input type="text" id="amount" style="border:0; color:#f6931f; font-weight:bold;" /></p>
<div id="slider-range" class="ui-slider ui-slider-horizontal ui-widget ui-widget-content ui-corner-all">
<a href="#" class="ui-slider-handle ui-state-default ui-corner-all" style="left: 20.1%;"></a>
<a href="#" class="ui-slider-handle ui-state-default ui-corner-all" style="left: 30.1%;"></a>
<a href="#" class="ui-slider-handle ui-state-disabled ui-corner-all" style="right: 99.5%;"></a>
<a href="#" class="ui-slider-handle ui-state-disabled ui-state-default ui-corner-all" style="left: 99.5%;"></a>
</div></div>
How can I make more handles active in same slider without overlapping them?