// == URL == //

function clearQueryStringKey(sURL, sKey) {
	sURL = sURL.toLowerCase();
	sKey = sKey.toLowerCase();
	var pos = sURL.indexOf("&" + sKey + "=");
	if (pos != -1) {
		sURL = sURL.replace(sURL.substring(pos, String(sURL + "&").indexOf("&", pos + 1)), "");
	}
	return sURL;
}

function getQueryStringValue(sURL, sKey) {
	sURL = sURL.toLowerCase();
	sKey = sKey.toLowerCase();
	var pos = sURL.indexOf("&" + sKey + "=");
	if (pos != -1) {
		return sURL.substring(pos + 2 + sKey.length, String(sURL + "&").indexOf("&", pos + 1));
	}
	return "";
}

//Most commonly used
function queryString(key) {
  var keys = window.location.search.substring(1).split("&");
  for (var L = 0; L < keys.length; L++) {
    var pair = keys[L].split("=");
    if (pair[0].toLowerCase() == key.toLowerCase()) {
      return pair[1];
    }
  }
  return null;
}

function addParameter(key, value) {
	return "&" + key + "=" + value;
}

//For simplicity
function qs(key) { return queryString(key); }
function addParam(key, value) { return addParameter(key, value); }