// option is a, b, c or d
// picture is number starting from 0
function toggle(option,picture) {
        for (var i = 0; i < 5; i++){
              if (document.getElementById(option + i) != null){
                  document.getElementById(option + i).style.display = 'none';
              }
        }
        document.getElementById(option + picture).style.display = 'inline';     
}