function /*out: String*/ number_format( /* in: float   */ number,
                                               /* in: integer */ laenge,
                                               /* in: String  */ sep,
                                               /* in: String  */ th_sep ) {
       
         number = Math.round( number * Math.pow(10, laenge) ) / Math.pow(10, laenge);
         str_number = number+"";
         arr_int = str_number.split(".");
         if(!arr_int[0]) arr_int[0] = "0";
         if(!arr_int[1]) arr_int[1] = "";
         if(arr_int[1].length < laenge){
           nachkomma = arr_int[1];
           for(i=arr_int[1].length+1; i <= laenge; i++){  nachkomma += "0";  }
           arr_int[1] = nachkomma;
         }
         if(th_sep != "" && arr_int[0].length > 3){
           Begriff = arr_int[0];
           arr_int[0] = "";
           for(j = 3; j < Begriff.length ; j+=3){
             Extrakt = Begriff.slice(Begriff.length - j, Begriff.length - j + 3);
             arr_int[0] = th_sep + Extrakt +  arr_int[0] + "";
           }
           str_first = Begriff.substr(0, (Begriff.length % 3 == 0)?3:(Begriff.length % 3));
           arr_int[0] = str_first + arr_int[0];
         }
         return arr_int[0]+sep+arr_int[1];
    }