JavaScript multi-level drop-down menu code (simple and practical)_navigation menu

<meta http-equiv="Content-Type" content="text/html; charset=gb2312"> <title>JavaScript drop-down menu</title> <style type="text/css"> * { padding:0; margin:0; } body { font-family:verdana, sans-serif; font-size:small; } #navigation, #navigation li ul { list-style-type:none; } #navigation { margin:20px; } #navigation li { float:left; text-align:center; position:relative; } #navigation li a:link, #navigation li a:visited { display:block; text-decoration:none; color:#000; width:120px; height:40px; line-height:40px; border:1px solid #fff; border-width:1px 1px 0 0; background:#c5dbf2; padding-left:10px; } #navigation li a:hover { color:#fff; background:#2687eb; } #navigation li ul li a:hover { color:#fff; background:#6b839c; } #navigation li ul { display:none; position:absolute; top:40px; left:0; margin-top:1px; width:120px; } #navigation li ul li ul { display:none; position:absolute; top:0px; left:130px; margin-top:0; margin-left:1px; width:120px; } </style> <ul id="navigation"> <li onmouseover="displaySubMenu(this)" onmouseout="hideSubMenu(this)"> <a href="#"> </a>Column 1<ul> <li> <a href="#"></a>Column 1->Menu 1</li> <li> <a href="#"></a>Column 1->Menu 2</li> <li> <a href="#"></a>Column 1->Menu 3</li> <li> <a href="#"></a>Column 1->Menu 4</li> </ul> </li> <li onmouseover="displaySubMenu(this)" onmouseout="hideSubMenu(this)"> <a href="#"> </a>Column 2<ul> <li> <a href="#"></a>Column 2->Menu 1</li> <li> <a href="#"></a>Column 2->Menu 2</li> <li> <a href="#"></a>Column 2->Menu 3</li> <li> <a href="#"></a>Column 2->Menu 4</li> <li> <a href="#"></a>Column 2->Menu 5</li> </ul> </li> <li onmouseover="displaySubMenu(this)" onmouseout="hideSubMenu(this)"> <a href="#"> </a>Column 3<ul> <li onmouseover="displaySubMenu(this)" onmouseout="hideSubMenu(this)"> <a href="#"> </a>Column 3->Menu 1<ul> <li> <a href="#"></a>Menu 1->Submenu 1</li> <li> <a href="#"></a>Menu 1->Submenu 2</li> <li> <a href="#"></a>Menu 1->Submenu 3</li> <li> <a href="#"></a>Menu 1->Submenu 4</li> </ul> </li> <li> <a href="#"></a>Column 3->Menu 2</li> <li onmouseover="displaySubMenu(this)" onmouseout="hideSubMenu(this)"> <a href="#"> </a>Column 3->Menu 3<ul> <li> <a href="#"></a>Menu 3->Submenu 1</li> <li> <a href="#"></a>Menu 3->Submenu 2</li> <li> <a href="#"></a>Menu 3->Submenu 3</li> </ul> </li> </ul> </li> </ul>