var ajax = function() {
 
var self = this; 
 
this.xmlHttp = null; 
this.success = null;
this.user_error = null; 
this.process_func = null;
this.params = null;
 
this.make_xmlHttp = function() {            
    if(window.XMLHttpRequest) 
    this.xmlHttp = new XMLHttpRequest();          
    else if(window.ActiveXObject)
    this.xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
} 
 
this.make_xmlHttp(); 
 
    this.post = function(url) {
 
        if(!this.ready_check()) { 
 
this.xmlHttp.open("POST", url, true);
 
this.xmlHttp.setRequestHeader('X-Requested-With', 'XmlHttpRequest');
this.xmlHttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded; charset=utf-8");
this.xmlHttp.setRequestHeader('Connection', 'Close');
 
this.xmlHttp.onreadystatechange = function() {
 
                if(self.xmlHttp.readyState == 1)
                    self.in_process();
 
                if(self.xmlHttp.readyState == 4)
                    if(self.xmlHttp.status == 200) {
self.success(self.get_response());
self.error('ERROR_NO_EXIST');
self.success = null;
                    }else
                         self.error(self.xmlHttp.status);
             }             
             this.xmlHttp.send(this.params_prepares());    
        }         
    }    
 
    this.get = function(url) {
 
        if(!this.ready_check()) { 
 
            if( !(/.*?$/.test(url)) ) 
                if( /=+/.test(url) ) { 
                    if(!(/.*&$/.test(url)))
                        url += '&';
                }else
                    url += '?';
 
url += this.params_prepares();
 
this.xmlHttp.open("GET", url, true);
 
this.xmlHttp.setRequestHeader('X-Requested-With', 'XmlHttpRequest'); 
this.xmlHttp.setRequestHeader("Content-type", "charset=utf-8");
this.xmlHttp.setRequestHeader('Connection', 'Close');
 
this.xmlHttp.onreadystatechange = function() {
                if(self.xmlHttp.readyState == 1)
                    self.in_process();
 
                if(self.xmlHttp.readyState == 4) 
                    if(self.xmlHttp.status == 200) { 
                        self.success(self.get_response());  
                        self.error('ERROR_NO_EXIST'); 
                        self.success = null; 
                    }else
                        self.error(self.xmlHttp.status);  
            }
 
            this.xmlHttp.send(null);       
        }     
    }      
 
this.xml = function(url) {
 
if(!this.ready_check()) { 
this.xmlHttp.open("POST", url, true); 
 
this.xmlHttp.setRequestHeader('X-Requested-With', 'XmlHttpRequest'); 
this.xmlHttp.setRequestHeader("Content-Type", "text/xml; charset=utf-8");
this.xmlHttp.setRequestHeader('Connection', 'Close');
 
this.xmlHttp.onreadystatechange = function() {
 
if(self.xmlHttp.readyState == 1)
self.in_process();
 
if(self.xmlHttp.readyState == 4)
if(self.xmlHttp.status == 200) { 
self.success(self.get_response());
self.error('ERROR_NO_EXIST');
self.success = null;
}else
self.error(self.xmlHttp.status);
}              
 
this.xmlHttp.send(this.params_prepares());    
}         
    }  
 
    this.ready_check = function() {                
 
if(this.xmlHttp == null) { 
alert("Error: xmlHttp should be an ajax obect(XMLHTTP).");
return true;
}
 
if(this.success == null) { 
alert("Error: success should be a function.");
return true;
}
 
         return false;
    }  
 
    this.error = function(data) {
        if(data == 'ERROR_NO_EXIST')
            self.user_error = null;
        else
            if(self.user_error != null) {
                self.user_error(data);
                self.user_error = null;
            }
    }
 
    this.in_process = function() {
        if(self.process_func != null) {
            self.process_func();
            self.process_func = null;
        }
    }
 
    this.params_prepares = function() {
        var params_str  = ''; 
        var params      = self.params;
 
        if(typeof params == 'string')
            params_str = params; 
        else{
            for(var key in params)
                params_str += encodeURIComponent(key) + '=' + encodeURIComponent(params[key])+ '&';
 
            params_str = params_str.substring(0, params_str.length - 1);
        }
 
        self.params = null;
 
        return params_str;
    }
 
    this.get_response = function() {
        var r_headers = self.xmlHttp.getResponseHeader('Content-Type'); 
 
        if(r_headers.indexOf('text/xml') != -1) 
            return self.xmlHttp.responseXML;
 
        if(r_headers.indexOf('text/html') != -1)
            return self.xmlHttp.responseText;
 
        if(r_headers.indexOf('application/json') != -1)
            return eval('(' + self.xmlHttp.responseText + ')');
    }
}