jQuery UI Slider with fixed minimum: show minimum range, not minimum absolute value?
===

I'm using a jQuery slider with a fixed minimum of 20, as [described in the docs][1].

However, it's not quite what I need. I'd like the visual range of the slider to be 0-100, but the user should never be allowed to move the slider to less than 20. 

In other words, the handle of the slider should never go all the way to the left-hand side of the slider (as it does at the moment), but should show the range 0-20. 

Here is [a JSFiddle to show what I mean][2], and here is the current code: 

    $("#range-slider").slider({
        range: "min",
        min: 20,
        max: 100, 
        value: 20,
        step: 20,
    });

Any ideas? 

  [1]: http://jqueryui.com/demos/slider/#rangemin
  [2]: http://jsfiddle.net/kGtsN/13/