/* 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.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();
}