JS: Replace URL Parameter

script.js

function replaceUrlParam(uri, key, value) {
  var re = new RegExp("([?&])" + key + "=.*?(&|$)", "i"),
      separator = uri.indexOf('?') !== -1 ? "&" : "?";

  if (uri.match(re)) {
    return uri.replace(re, '$1' + key + "=" + value + '$2');
  } else {
    return uri + separator + key + "=" + value;
  }
}