How can i add a sub-sub menu with CSS - html

Question

Im trying to do a sub-sub menu in a webpage. I tried following the help in this post: how do I make a sub sub menu with css? but to be honest i didnt understand what code i had to add in each class and when i tried it didnt show anything. Here is the code of the menu:
<div class="l7menu">
<ul class="dpdown">
<li class="mainlist">Hombres
<ul class="sub_menu">
Prueba
Here goes the sub-submenu
<ul>
<li> Item 1 </li>
<li> Item 2 </li>
</ul>
</ul>
</li>
</ul>
</div>
Also the CSS of the classes are these ones (The sub_menu and l7menu class dont have any style applied):
.mainlist {
border-bottom: 2px solid #EAD704;
background: none;
margin-left: 2px !important;
}
.mainlist:hover {
color: #EAD704 !important;
}
ul.dpdown {
float: right;
position: relative;
z-index: 1000;
}
ul.dpdown li {
font-weight: bold;
float: left;
zoom: 1;
display: inline;
line-height: 20px;
list-style: none outside none;
margin-left: -25px;
}
ul.dpdown a:hover {
color: #EAD704;
}
ul.dpdown a:active {
color: #FFFFFF;
}
ul.dpdown li a {
color: #e8e8e8;
display: block;
padding-bottom: 4px;
text-align: center;
width: 150px;
}
ul.dpdown li:last-child a {
border-right: none;
} /* Doesn't work in IE */
ul.dpdown li.hover, ul.dpdown li:hover {
color: black;
position: relative;
}
ul.dpdown li.hover a {
color: white;
}
/*
LEVEL TWO
*/
ul.dpdown ul {
width: 150px;
visibility: hidden;
position: absolute;
top: 100%;
left: 0;
}
ul.dpdown ul li {
font-weight: normal;
background: #333;
color: #000;
float: none;
}
/* IE 6 & 7 Needs Inline Block */
ul.dpdown ul li a {
background-color: #101010;
border-right: medium none;
display: inline-block;
margin-top: 2px;
padding: 10px 0;
width: 150px;
font-size: 13px;
color: #999999;
}
ul.dpdown ul li a:hover {
background-color: #222222;
}
/*
LEVEL THREE
*/
ul.dpdown ul ul {
left: 100%;
top: 0;
}
ul.dpdown li:hover > ul {
visibility: visible;
}
As always thank you very very much !

Answer 1

Here's a FIDDLE, I fixed your CSS a little.
Your HTML should look like this
<div class="l7menu">
<ul class="dpdown">
<li class="mainlist">Hombres
<ul class="sub_menu">
<li>Prueba</li>
<li>Here goes the sub-submenu
<ul>
<li>Item 1</li>
<li>Item 2</li>
<li>Item 3</li>
<li>Item 4</li>
<li>Item 5</li>
</ul>
</li>
</ul>
</li>
<li>Item 2</li>
<li>Item 3</li>
</ul>
</div>