UI Slider
HTML
<input type="text" id="amount" value="40" />
<div id="slider-range"></div>
JavaScript
var valMap = [0, 25, 50, 75, 100];
$("#slider-range").slider({
min: 1,
max: valMap.length - 1,
value: 0,
slide: function(event, ui) {
$("#amount").val(valMap[ui.value]);
}
});