How to get currency using Javascript or PHP

currency.js

/*
  @author Jefrey S. Santos <github.com/jesobreira>
*/

function currency(icoin1, icoin2, value, callback) {
  if(typeof value == 'undefined') value = 1;

  icoin1 = icoin1.toUpperCase();
  icoin2 = icoin2.toUpperCase();
  value = parseFloat(value);

  var url = 'https://query.yahooapis.com/v1/public/yql?q=select%20*%20from%20yahoo.finance.xchange%20where%20pair%20%3D%20%27'+icoin1+icoin2+'%27&format=json&diagnostics=true&env=store%3A%2F%2Fdatatables.org%2Falltableswithkeys&callback=';
  $.getJSON(url, function(data) {
    theval = parseFloat((data.query.results.rate.Rate)*value);
    callback(theval);
  }, function() {
    console.error('error fetching currency url');
  })
}

// Example:

currency('btc', 'usd', 2, function(val) {
  alert("2 bitcoins are the same as US$ "+val);
});

currency.php

<?php
/*
  @author Jefrey S. Santos <github.com/jesobreira>
*/

function currency($icoin2, $icoin1, $value=1) {
	$coin1 = strtoupper($icoin1);
	$coin2 = strtoupper($icoin2);
	$coin1 = preg_replace("/[^A-Z{3}]/", null, $coin1);
	$coin2 = preg_replace("/[^A-Z{3}]/", null, $coin2);
	$currency = @file_get_contents('http://download.finance.yahoo.com/d/quotes.csv?s='.$coin2.$coin1.'=X&f=sl1d1t1ba&e=.csv');
	$currency = explode(",", $currency);
	$value = (float)($currency[1]*$value);
	return $value;
}

$val = currency('btc', 'brl', 2);
echo "2 bitcoins are the same as US$ ".$val;