this.promena = 0;
                      this.stav = 0;
                                            
change_background_a = function(elementID, className) {
   var element = document.getElementById(elementID);
   if (element.className == 'aktivni') {stav=1;}                     
   if(promena==0){
    if (element) {
	    element.className = className;
      //		element.style.top = '10 px';
      //		element.style.display = '';
    }
   }
   promena = 0;
   return false;
}
                      
change_background_p = function(elementID, className) {
   var element = document.getElementById(elementID);               	                     
	 if (stav==0){
   if(promena==0){
   if (element) {
      element.className = className;
      //		element.style.top = '10 px';
     //		element.style.display = '';
   }
   }
   }
   stav=0; 
   promena = 0;
   return false;
}
                      
visible = function (elementID1, elementID2, elementID3, elementID4, elementID5, elementID6){          
	  var element1 = document.getElementById(elementID1);
	  var element2 = document.getElementById(elementID2);
	  var element3 = document.getElementById(elementID3);
	  var element4 = document.getElementById(elementID4);
	  var element5 = document.getElementById(elementID5);
	  var element6 = document.getElementById(elementID6);
               
                      
    element1.style.display = 'block';
    element1.style.visibility = 'visible';
    element4.className = 'aktivni';
    promena = 1;
                                                                       
    element2.style.display = 'none';
    element2.style.visibility='hidden';
    element5.className = 'passive';
                                                
    element3.style.display = 'none';
    element3.style.visibility='hidden';
    element6.className = 'passive';
                        
                                              
    return false;
}