function si(n, i) { 
  
  var x = document.getElementById(n);
  x.src=i;
  
}
  
function swap_img(n, i) { 

  var x = document.getElementById(n);
  x.src=i
  
}

function popup(x) { 

  document.getElementById(x).style.display = 'block';
  
}

function close(x) { 

  document.getElementById(x).style.display = 'none';
  
}