function strpos(haystack, needle, offset) {
    var i = (haystack+'').indexOf(needle, (offset || 0));
    return i === -1 ? false : i;
}

function str_replace(haystack, needle, replacement){
  var temp = haystack.split(needle);
  return temp.join(replacement);
}

function empty(mixed_var) {
    // http://kevin.vanzonneveld.net
    // +   original by: Philippe Baumann
    // +      input by: Onno Marsman
    // +   bugfixed by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // +      input by: LH
    // +   improved by: Onno Marsman
    // +   improved by: Francesco
    // +   improved by: Marc Jansen
    // +   input by: Stoyan Kyosev (http://www.svest.org/)
    // *     example 1: empty(null);
    // *     returns 1: true
    // *     example 2: empty(undefined);
    // *     returns 2: true
    // *     example 3: empty([]);
    // *     returns 3: true
    // *     example 4: empty({});
    // *     returns 4: true
    // *     example 5: empty({'aFunc' : function () { alert('humpty'); } });
    // *     returns 5: false

    var key;

    if (mixed_var === "" ||
        mixed_var === 0 ||
        mixed_var === "0" ||
        mixed_var === null ||
        mixed_var === false ||
        typeof mixed_var === 'undefined'
    ){
        return true;
    }

    if (typeof mixed_var == 'object') {
        for (key in mixed_var) {
            return false;
        }
        return true;
    }

    return false;
}

function trim(string){
  return string.replace(/(^\s+)|(\s+$)/g, "");
}