SO fiddle

Test Fiddle mainly for SO Questions

by Nick Craver

HTML

<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.4/themes/overcast/jquery-ui.css">
EUR-total: <input type="texRunt" id="EUR-total" />

JavaScript

var returned_values = { "aaData": 
[["Aug 2010","www.website.com","EUR","562.48","100%","562.48"],
["Aug 2010","www.website.com","EUR","4.80","100%","4.80"],
["Aug 2010","www.website.com","GBP","839.79","100%","839.79"],
 ["Jun 2010","www.website.com","USD","266.80","100%","266.80"],] };


var eur_total = 0;
$.each(returned_values && returned_values.aaData || {}, function(index, item) {
   if(item[2] == "EUR") eur_total += parseFloat(item[3]);
});
$('#EUR-total').val(eur_total);