function zobraz(name) {
    
  	element = document.getElementById(name).style;
  	element.display = 'block';
  	
  	element = document.getElementById(name + '_on').style;
  	element.display = 'block';
  	
  	element = document.getElementById(name + '_off').style;
  	element.display = 'none';
  	
  
  	
  }
  
  function skryj(name) {
   
  	element = document.getElementById(name).style;
  	element.display = 'none';
  	
  	element = document.getElementById(name + '_on').style;
  	element.display = 'none';
  	
  	element = document.getElementById(name + '_off').style;
  	element.display = 'block';
  	
  }