/* 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.onSuccess = 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();
                                        self.onSuccess();   
                                   } else {
                                        self.onError();
                                   }

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

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