var ve = navigator.userAgent.indexOf("ozilla/");
var mainv = parseInt( navigator.userAgent.charAt(ve+7) );

 // ------------- class item ----------------
   function item(name)
     { this.name        = name;
       this.img_on      = new Image();
       this.img_on.src  = "images/"+name+"_on.gif"; 
       this.img_off     = new Image();
       this.img_off.src = "images/"+name+"_off.gif"; 
     }
  
 // ----------------- class obmysh --------------
    function search( name )
       {   if (this._array.length == null) return null;

           for(var i = 0; i < this._array.length; ++i)
              { 
                if ( this._array[i] != null &&
                          this._array[i].name == name ) return i; 
              }
         return null;
       }

   function _load(name)
     { 
        var nextElement = (this._array.length == null) ? 0 : this._array.length;
        this._array[nextElement] = new item(name);
     }

/*----- main ---- */
function obmysh()
     {
       this._array = new Array();

       this.load = _load;
       this.search = search;
     }

/*----------------------------*/
_obmysh  = new obmysh();

/*----------------------------*/

function msOn(name) 
{
 if ( mainv >= 4 )
 { var q = _obmysh.search(name);
   if (q != null) document.images[ name ].src = _obmysh._array[q].img_on.src ;
 }
}

function msOff(name) 
{
 if ( mainv >= 4 )
 { var q = _obmysh.search(name);
   if (q != null) document.images[ name ].src = _obmysh._array[q].img_off.src ;
 }
}

function img(name)
{
  _obmysh.load(name);
}