function showlayer(lay) {



  LiczbaPodmenu = 31; 

      for( k=1 ; k<=LiczbaPodmenu ; k=k+1 ) 
        { 
         if(k != lay){
            document.getElementById('dzien'+k).style.display = 'none'
            }
            else 
            {
            document.getElementById('dzien'+k).style.display = 'block'
            }
        }
           
    
    


}