<?php
function currency_format($num,$currency='USD')
{
    $str = '';
    $format = number_format($num,2, '.', ',');

    switch($currency)
    {
        case 'USD': $str .= '$'.$format ;
            break;
        /* case 'PHP':
            break; */
    }
return $str;
}

echo currency_format(1000)."<br />";
echo currency_format(1202100);
?>