/**
*
*  Javascript string replace
 Javascript has a built-in string replace function but it uses regular expressions. Here you will fint two versions of custom string replace functions
*
**/
// standard string replace functionality
function str_replace(haystack, needle, replacement) {
    var temp = haystack.split(needle);
    return temp.join(replacement);
}
// needle may be a regular expression
function str_replace_reg(haystack, needle, replacement) {
    var r = new RegExp(needle, 'g');
    return haystack.replace(r, replacement);
}