need a code to write drop down menu in css and html

CSS3 Metal menu with icons

#nav {
    border:3px solid #3e4547;

    box-shadow:2px 2px 8px #000000;
    border-radius:3px;
    -moz-border-radius:3px;
    -webkit-border-radius:3px;
}
#nav, #nav ul {
    list-style:none;
    padding:0;
    width:200px;
}
#nav ul {
    position:relative;
    z-index:-1;
}
#nav li {
    position:relative;
    z-index:100;
}
#nav ul li {
    margin-top:-23px;

    -moz-transition:  0.4s linear 0.4s;
    -ms-transition: 0.4s linear 0.4s;
    -o-transition: 0.4s linear 0.4s;
    -webkit-transition: 0.4s linear 0.4s;
    transition: 0.4s linear 0.4s;
}
#nav li a {
    background-color:#d4d5d8;
    color:#000;
    display:block;
    font-size:12px;
    font-weight:bold;
    line-height:28px;
    outline:0;
    padding-left:15px;
    text-decoration:none;
}
#nav li a.sub {
    background:#d4d5d8 url("../images/down.gif") no-repeat;
}
#nav li a + img {
    cursor:pointer;
    display:none;
    height:28px;
    left:0;
    position:absolute;
    top:0;
    width:200px;
}
#nav li a img {
    border-width:0px;
    height:24px;
    line-height:28px;
    margin-right:8px;
    vertical-align:middle;
    width:24px;
}
#nav li a:hover {
    background-color:#bcbdc1;
}
#nav ul li a {
    background-color:#eee;
    border-bottom:1px solid #ccc;
    color:#000;
    font-size:11px;
    line-height:22px;
}
#nav ul li a:hover {
    background-color:#ddd;
    color:#444;
}
#nav ul li a img {
    background: url("../images/bulb.png") no-repeat;
    border-width:0px;
    height:16px;
    line-height:22px;
    margin-right:5px;
    vertical-align:middle;
    width:16px;
}
#nav ul li:nth-child(odd) a img {
    background:url("../images/bulb2.png") no-repeat;
}
#nav a.sub:focus {
    background:#bcbdc1;
    outline:0;
}
#nav a:focus ~ ul li {
    margin-top:0;

    -moz-transition:  0.4s linear;
    -ms-transition: 0.4s linear;
    -o-transition: 0.4s linears;
    -webkit-transition: 0.4s linears;
    transition: 0.4s linear;
}
#nav a:focus + img, #nav a:active + img {
    display:block;
}
#nav a.sub:active {
    background:#bcbdc1;
    outline:0;
}
#nav a:active ~ ul li {
    margin-top:0;
}
#nav ul:hover li {
    margin-top:0;
}



ul.sub-level {
    display: none;
}


#nav li a.sub-level {
    background:#d4d5d8 url("../images/down.gif") no-repeat;
}

#nav a.sub-level:focus {
    background:#bcbdc1;
    outline:0;
}
#nav a.sub-level:active {
    background:#bcbdc1;
    outline:0;
}