how to make list horizontal in html

#menu ul{
  list-style: none;
}
#menu li{
  display: inline;
}

#div_top_hypers {
    background-color:#eeeeee;
    display:inline;      
}
#ul_top_hypers li{
    display: inline;
}

HTML Code --->
<div id="menu">
  <ul>
    <li>First menu item</li>
    <li>Second menu item</li>
    <li>Third menu item</li>
  </ul>
</div>

CSS Code --->
#menu ul{
  list-style: none;
}
#menu li{
  display: inline;
}