<style>
#map { position:absolute; top:0; bottom:0; width:100%; }
#currency {
z-index:9999;
position:absolute;
bottom:10px;
left:10px;
font-size:36px;
font-weight:bold;
}
</style>
<div id='currency'></div>
<div id='map'></div>
<script>
var map = L.mapbox.map('map', 'examples.map-zmy97flj');
// This is example 'external data'. It's obviously very much an example,
// and in practice you'll want to use jQuery's .ajax to pull in data or
// you already have it in some other form. The important part is that
// this data has a key, like 'Canada', which exactly matches part of the
// data in the tileset - here it's that the key is the same as o.data.admin
var currencies = {
'United States of America': 'USD',
'Canada': 'CAD',
'Mexico': 'MXN'
};
var currency = document.getElementById('currency');
// This tileset, Geography Class, has interactivity defined in TileMill
// and displayed in its tooltips. If you're creating a new tileset to use
// with this technique, see the documentation on defining tooltips:
// > http://mapbox.com/tilemill/docs/crashcourse/tooltips/
// and you'll need to use fields for them to be available here -
// to hide them in tooltips but use them here, you can use something like
//
// <span style='display:none'>}</span>
//
// in the tooltip content to get TileMill to detect that the field }
// should be available in interaction.
map.gridLayer
.on('mousemove',function(o) {
document.getElementById('currency').innerHTML = (o.data && currencies[o.data.admin]) || '';
}).on('mouseout', function(o) {
document.getElementById('currency').innerHTML = '';
});
</script>