Simple HTML slidebar – works on mobile

<!DOCTYPE html>
<html>
<head>
<style type="text/css">

#bar{
    width:200px;
    height:25px;
    border:1px solid black;
    position:relative;
}

#slider{
    width:0%;
    height:100%;
    background-color:red;
    top:0px;
    left:0px;
    position:absolute;
    cursor:pointer;
}

#info{
    width:200px;
    height:25px;
    border:1px solid black; 
}

</style>

<script type="text/javascript">
var bar, slider;

function init(){

    bar = document.getElementById('bar');
    slider = document.getElementById('slider');
    info = document.getElementById('info');
    bar.addEventListener('mousedown', startSlide, false);   
    bar.addEventListener('mouseup', stopSlide, false);
}

function startSlide(event){
    var set_perc = ((((event.clientX - bar.offsetLeft) / bar.offsetWidth)).toFixed(2));
    info.innerHTML = 'start' + set_perc + '%';  
    bar.addEventListener('mousemove', moveSlide, false);    
    slider.style.width = (set_perc * 100) + '%';    
}

function moveSlide(event){
    var set_perc = ((((event.clientX - bar.offsetLeft) / bar.offsetWidth)).toFixed(2));
    info.innerHTML = 'moving : ' + set_perc + '%';
    slider.style.width = (set_perc * 100) + '%';
}

function stopSlide(event){
    var set_perc = ((((event.clientX - bar.offsetLeft) / bar.offsetWidth)).toFixed(2));
    info.innerHTML = 'done : ' + set_perc + '%';
    bar.removeEventListener('mousemove', moveSlide, false);
    slider.style.width = (set_perc * 100) + '%';
}

</script>

</head>
<body onload='init()'>

<div id='bar'>
<div id='slider'>

</div>
</div>
<br />

<div id='info'>info</div>

</body>
</html>