function class_http_request(){

    //http-request objekt
    var http=null;

    //var http_pfad="http://83.151.31.13/~pirna-altstadt/map_project/";
    var http_pfad="http://"+parent.location.hostname+"/";
    var caller=null;
    var status1=false;
    var status2=false;
    var query_string=null;

    //öffentliche methode request starten
    this.start_request=function(obj,state1,state2){
        //window.my_loader.show_loader();
        caller=obj;
        status1=state1;
        status2=state2;

        if (window.XMLHttpRequest) {
            http = new XMLHttpRequest();
        }
        else if (window.ActiveXObject) {
            http = new ActiveXObject("Microsoft.XMLHTTP");
        }
        if (http != null) {

            http.open("GET", http_pfad+"php/map.php"+query_string, true);
            http.onreadystatechange = init;
            http.send(null);
        }
        return;
    }

    //post-request
    this.start_post_request=function(obj,my_value){
        //window.my_loader.show_loader();
        caller=obj;
        if (window.XMLHttpRequest) {
            http = new XMLHttpRequest();
        }
        else if (window.ActiveXObject) {
            http = new ActiveXObject("Microsoft.XMLHTTP");
        }
        if (http != null) {
            http.open("POST", http_pfad+"php/getpost.php", true);
            http.onreadystatechange = init;
            http.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
            http.send(query_string);
        }
        return;
    }

    //private methode **ausgeben**
    function init(){

        if (http.readyState == 4) {
            window.my_loader.hide_loader();
            var daten = http.responseText;
            
            if(status1){
                caller.calling1(daten);
            }
            else if(status2){
                caller.calling2(daten);
            }
            else{
                caller.calling(daten);
            }

            return;
        }
    }
    
    this.set_query=function(my_value){
        query_string=my_value;
    }

}