(function() {
  String.prototype.trim = function() {
    return this.replace(/^\s+/g, '').replace(/\s+$/g, '');
  }

  String.prototype.repeat = function(num) {
    for (var i = 0, buf = ""; i < num; i++) buf += this;
    return buf;
  }

  String.prototype.truncate = function(length) {
    if (this.length > length) {
      return this.slice(0, length - 3) + "...";
    } else {
      return this;
    }
  }

  String.prototype.slugify = function(sep) {
    if (typeof sep == 'undefined') sep = '_';
    var alphaNumRegexp = new RegExp('[^a-zA-Z0-9\\' + sep + ']', 'g');
    var avoidDuplicateRegexp = new RegExp('[\\' + sep + ']{2,}', 'g');
    return this.replace(/\s/g, sep).replace(alphaNumRegexp, '').replace(avoidDuplicateRegexp, sep).toLowerCase()
  }

  window.addParameterToURL = function(key, value) { // code from http://stackoverflow.com/questions/486896/adding-a-parameter-to-the-url-with-javascript
    key = encodeURIComponent(key); value = encodeURIComponent(value);

    var kvp = document.location.search.substr(1).split('&');

    var i = kvp.length; var x; while(i--) {
      x = kvp[i].split('=');

      if (x[0] == key) {
        x[1] = value;
        kvp[i] = x.join('=');
        break;
      }
    }

    if (i < 0) { kvp[kvp.length] = [key,value].join('='); }

    //this will reload the page, it's likely better to store this until finished
    document.location.search = kvp.join('&');
  }
})();