$us_price = '100';

$ticker= 'CADUSD=X';
$open = fopen("http://quote.yahoo.com/d/quotes.csv?s=$ticker&f=sl1d1t1c1ohgv&e=.csv", "r");
$exchange_rate = fread($open, 2000);
fclose($open);
$exchange_rate = str_replace("\"", "", $exchange_rate);
$exchange_rate = explode(",", $exchange_rate);
$ca_price = ($us_price/$exchange_rate[1]);
$price = number_format ($ca_price, 2);

echo "$us_price US dollars = \$$price Canadian dollars";