/* Simple AJAX Code-Kit (SACK) v1.6.1 */
/* ©2005 Gregory Wild-Smith */
/* www.twilightuniverse.com */
/* Software licenced under a modified X11 licence,
   see documentation or authors website for more details */

function sack(file) {
  this.xmlhttp = null;
  this.serializeForm=function(options)
  {
    var defaultOptions={formObject:document.forms[0],encodeValues:false,includeEmptyValues:false};
    for( var opt in options )
    {
      defaultOptions[opt]=options[opt];
    }
    if( !defaultOptions.formObject )
      return null;

    var f=defaultOptions.formObject;
    defaultOptions.encodeValues = defaultOptions.encodeValues ? encodeURIComponent : function(str){return str;};

    var params = {};
    for( var i=0, limit=f.elements.length; i < limit; ++i)
    {
      if( defaultOptions.includeEmptyValues==false && f.elements[i].value=="" )
      {
	continue;
      }
      var key=null;
      switch( String(f.elements[i].type).toUpperCase() )
      {
	case "TEXT":
	  case "SUBMIT":
	  case "HIDDEN":
	  case "PASSWORD":
	  key=f.elements[i].name;
	break;

	case "CHECKBOX":
	  case "RADIO":
	  if( f.elements[i].checked )
	  {
	    key=f.elements[i].name;
	  }
	break;

	default:
	switch( String(f.elements[i].tagName).toUpperCase() )
	{
	  case "TEXTAREA":
	    case "SELECT":
	    key=f.elements[i].name;
	  break;
	}
	break;
      }
      if( key )
      {
	if( typeof(params[key]) === "undefined" )
	{
	  params[key]=defaultOptions.encodeValues(f.elements[i].value);
	}
	else
	{
	  if("string"==typeof(params[key]))
	  {
	    var temp = params[key];
	    params[key]= new Array(temp);
	  }
	  params[key].push( defaultOptions.encodeValues(f.elements[i].value) );
	}
      }
    }

    for( var fieldName in params )
    {
      if( typeof(params[fieldName]) =="string" )
      {
	this.setVar(fieldName , params[fieldName] );
      }
      else
      {
	for( var i =0,limit=params[fieldName].length; i < limit; ++i)
	{
	  this.setVar(fieldName,params[fieldName][i]);
	}
      }
    }
    return params;
  };


  this.resetData = function() {
    this.method = "POST";
    this.queryStringSeparator = "?";
    this.argumentSeparator = "&";
    this.URLString = "";
    this.encodeURIString = true;
    this.execute = false;
    this.element = null;
    this.elementObj = null;
    this.requestFile = file;
    this.vars = new Object();
    this.responseStatus = new Array(2);
  };

  this.resetFunctions = function() {
    this.onLoading = function() { };
    this.onLoaded = function() { };
    this.onInteractive = function() { };
    this.onCompletion = function() { };
    this.onError = function() { };
    this.onFail = function() { };
  };

  this.reset = function() {
    this.resetFunctions();
    this.resetData();
  };

  this.createAJAX = function() {
    try {
      this.xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
    } catch (e1) {
      try {
	this.xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
      } catch (e2) {
	this.xmlhttp = null;
      }
    }

    if (! this.xmlhttp) {
      if (typeof XMLHttpRequest != "undefined") {
	this.xmlhttp = new XMLHttpRequest();
      } else {
	this.failed = true;
      }
    }
  };

  this.setVar = function(name, value){
    this.vars[name] = Array(value, false);
  };

  this.encVar = function(name, value, returnvars) {
    if (true == returnvars) {
      return Array(encodeURIComponent(name), encodeURIComponent(value));
    } else {
      this.vars[encodeURIComponent(name)] = Array(encodeURIComponent(value), true);
    }
  }

  this.processURLString = function(string, encode) {
    encoded = encodeURIComponent(this.argumentSeparator);
    regexp = new RegExp(this.argumentSeparator + "|" + encoded);
    varArray = string.split(regexp);
    for (i = 0; i < varArray.length; i++){
      urlVars = varArray[i].split("=");
      if (true == encode){
	this.encVar(urlVars[0], urlVars[1]);
      } else {
	this.setVar(urlVars[0], urlVars[1]);
      }
    }
  }

  this.createURLString = function(urlstring) {
    if (this.encodeURIString && this.URLString.length) {
      this.processURLString(this.URLString, true);
    }

    if (urlstring) {
      if (this.URLString.length) {
	this.URLString += this.argumentSeparator + urlstring;
      } else {
	this.URLString = urlstring;
      }
    }

    // prevents caching of URLString
    this.setVar("rndval", new Date().getTime());

    urlstringtemp = new Array();
    for (key in this.vars) {
      if (false == this.vars[key][1] && true == this.encodeURIString) {
	encoded = this.encVar(key, this.vars[key][0], true);
	delete this.vars[key];
	this.vars[encoded[0]] = Array(encoded[1], true);
	key = encoded[0];
      }

      urlstringtemp[urlstringtemp.length] = key + "=" + this.vars[key][0];
    }
    if (urlstring){
      this.URLString += this.argumentSeparator + urlstringtemp.join(this.argumentSeparator);
    } else {
      this.URLString += urlstringtemp.join(this.argumentSeparator);
    }
  }

  this.runResponse = function() {
    eval(this.response);
  }

  this.runAJAX = function(urlstring) {
    if (this.failed) {
      this.onFail();
    } else {
      this.createURLString(urlstring);
      if (this.element) {
	this.elementObj = document.getElementById(this.element);
      }
      if (this.xmlhttp) {
	var self = this;
	if (this.method == "GET") {
	  totalurlstring = this.requestFile + this.queryStringSeparator + this.URLString;
	  this.xmlhttp.open(this.method, totalurlstring, true);
	} else {
	  this.xmlhttp.open(this.method, this.requestFile, true);
	  try {
	    this.xmlhttp.setRequestHeader("Content-Type", "application/x-www-form-urlencoded")
	  } catch (e) { }
	}

	this.xmlhttp.onreadystatechange = function() {
	  switch (self.xmlhttp.readyState) {
	    case 1:
	      self.onLoading();
	      break;
	    case 2:
	      self.onLoaded();
	      break;
	    case 3:
	      self.onInteractive();
	      break;
	    case 4:
	      self.response = self.xmlhttp.responseText;
	      self.responseXML = self.xmlhttp.responseXML;
	      self.responseStatus[0] = self.xmlhttp.status;
	      self.responseStatus[1] = self.xmlhttp.statusText;

	      if (self.execute) {
		self.runResponse();
	      }

	      if (self.elementObj) {
		elemNodeName = self.elementObj.nodeName;
		elemNodeName.toLowerCase();
		if (elemNodeName == "input"
		    || elemNodeName == "select"
		    || elemNodeName == "option"
		    || elemNodeName == "textarea") {
		  self.elementObj.value = self.response;
		} else {
		  self.elementObj.innerHTML = self.response;
		}
	      }
	      if (self.responseStatus[0] == "200") {
		self.onCompletion();
	      } else {
		self.onError();
	      }

	      self.URLString = "";
	      break;
	  }
	};

	this.xmlhttp.send(this.URLString);
      }
    }
  };

  this.reset();
  this.createAJAX();
}