Capturing jRange's change event

HTML

<script src="http://apartmany.jinda.cz/js/min/jquery.range-min.js"></script>
<p>&nbsp;</p>
<input type="hidden" class="single-slider" id="test"  />

CSS

.slider-container {
    width: 300px;
    font-family:"Helvetica Neue", Helvetica, Arial, sans-serif;
}
.slider-container .back-bar {
    height: 10px;
    position: relative;
}
.slider-container .back-bar .selected-bar {
    position: absolute;
    height: 100%;
}
.slider-container .back-bar .pointer {
    position: absolute;
    width: 10px;
    height: 10px;
    background-color: red;
    cursor: col-resize;
    opacity: 1;
    z-index: 2;
}
.slider-container .back-bar .pointer.last-active {
    z-index: 3;
}
.slider-container .back-bar .pointer-label {
    position: absolute;
    top: -17px;
    font-size: 8px;
    background: white;
    white-space: nowrap;
    line-height: 1;
}
.slider-container .back-bar .focused {
    z-index: 10;
}
.slider-container .clickable-dummy {
    cursor: pointer;
    position: absolute;
    width: 100%;
    height: 100%;
    z-index: 1;
}
.slider-container .scale {
    top: 2px;
    position: relative;
}
.slider-container .scale span {
    position: absolute;
    height: 5px;
    border-left: 1px solid #999;
    font-size: 0;
}
.slider-container .scale ins {
    font-size: 9px;
    text-decoration: none;
    position: absolute;
    left: 0;
    top: 5px;
    color: #999;
    line-height: 1;
}
.slider-container.slider-readonly .clickable-dummy, .slider-container.slider-readonly .pointer {
    cursor: auto;
}
.theme-green .back-bar {
    height: 5px;
    border-radius: 2px;
    background-color: #eeeeee;
    background-color: #e7e7e7;
    background-image: -moz-linear-gradient(top, #eeeeee, #dddddd);
    background-image: -webkit-gradient(linear, 0 0, 0 100%, from(#eeeeee), to(#dddddd));
    background-image: -webkit-linear-gradient(top, #eeeeee, #dddddd);
    background-image: -o-linear-gradient(top, #eeeeee, #dddddd);
    background-image: linear-gradient(to bottom, #eeeeee, #dddddd);
    background-repeat: repeat-x;
    filter: progid:DXImageTransform.Microsoft.gradient(startColorstr='#ffeeeeee', endColorstr='#ffdddddd',...

JavaScript

$('#test').jRange({
    from: 0,
    to: 100,
    step: 1,
    scale: [0, 25, 50, 75, 100],
    format: '$%s',
    width: 300,
    theme: "theme-blue",
    showLabels: true,
    onstatechange: function (value) {
        console.log(value);
    }
});

$('#test').jRange('setValue', '23, 50');