/* 

Unobtrusive Javascript functions for use in formscripts.js and 
slideshow.js. 

(CC) 2006 Mark Perkins. Some Rights Reserved.
Contact: mark@perkwebdesign.com

This script is licenced under the Creative Commons 
Attribution-ShareAlike 2.5 License. 
To view a copy of this licence, visit 
http://creativecommons.org/licenses/by-sa/2.5/

*/

/* simple array randomizing function
===================================================================*/

function compare(a, b) {
  if (Math.random() * 2 > 1) { return 1; }
  else { return -1; }
}

/* prototype of push function to allow for IE
===================================================================*/

Array.prototype.push = function() {
  for (var i = 0; i < arguments.length; i++) {
    this[this.length] = arguments[i];
  }
  return arguments[i - 1];
};

/* addclass, removeclass and getElementByAttribute functions
===================================================================*/

function addClass(target, classValue) {
  var pattern = new RegExp("(^| )" + classValue + "( |$)");

  if (!pattern.test(target.className)) {
    if (target.className == "") {
      target.className = classValue;
    }
    else {
      target.className += " " + classValue;
    }
  }
  return true;
}

function removeClass(target, classValue) {
  var removedClass = target.className;
  var pattern = new RegExp("(^| )" + classValue + "( |$)");
  removedClass = removedClass.replace(pattern, "$1");
  removedClass = removedClass.replace(/ $/, "");
  target.className = removedClass;
  return true;
}

function getElementsByAttribute(attribute, attributeValue) {
  var elementArray = new Array();
  var matchedArray = new Array();
  if (document.all) {
    elementArray = document.all;
  } else {
    elementArray = document.getElementsByTagName("*");
  }
  for (var i = 0; i < elementArray.length; i++)
  {
    if (attribute == "class") {
      var pattern = new RegExp("(^| )" + attributeValue + "( |$)");
      if (pattern.test(elementArray[i].className)) {
        matchedArray[matchedArray.length] = elementArray[i];
      }
    } else if (attribute == "for") {
      if (elementArray[i].getAttribute("htmlFor") || elementArray[i].getAttribute("for")) {
        if (elementArray[i].phpFor == attributeValue) {
          matchedArray[matchedArray.length] = elementArray[i];
        }
      }
    } else if (elementArray[i].getAttribute(attribute) == attributeValue) {
      matchedArray[matchedArray.length] = elementArray[i];
    }
  }
  return matchedArray;
}

/* event and load listeners
===================================================================*/

function attachEventListener(target, eventType, functionRef, capture)
{
  if (typeof target.addEventListener != "undefined") {
    target.addEventListener(eventType, functionRef, capture);
  }
  else if (typeof target.attachEvent != "undefined") {
    var functionString = eventType + functionRef;
    target["e" + functionString] = functionRef;
    target[functionString] = function(event) {
      if(typeof event == "undefined"){event = window.event}; target["e" + functionString](event);
    };
    target.attachEvent("on" + eventType, target[functionString]);
  }
  else {
    eventType = "on" + eventType;
    if (typeof target[eventType] == "function") {
      var oldListener = target[eventType];
      target[eventType] = function() {
        oldListener();
        return functionRef();
      }
    } else {
      target[eventType] = functionRef;
    }
  }
  return true;
}

function detachEventListener(target, eventType, functionRef, capture){
  if (typeof target.removeEventListener != "undefined") {
    target.removeEventListener(eventType, functionRef, capture)
  } else if (typeof target.detachEvent != "undefined") {
    var functionString = eventType + functionRef;
    target.detachEvent("on" + eventType, target[functionString]);
    target["e" + functionString] = null;
    target[functionString] = null;
  } else {
    target["on" + eventType] = null;
  }
  return true;
}

function addLoadListener(fn) {
  if (typeof window.addEventListener != 'undefined') {
    window.addEventListener('load', fn, false);
  } else if (typeof document.addEventListener != 'undefined') {
    document.addEventListener('load', fn, false);
  } else if (typeof window.attachEvent != 'undefined') {
    window.attachEvent('onload', fn);
  } else {
    var oldfn = window.onload;
    if (typeof window.onload != 'function') {
      window.onload = fn;
    } else {
      window.onload = function() {
        oldfn();
        fn();
      };
    }
  }
}