How to create sub menu in side menu in html & css - html

Question

I have 1 side menu in my main page of website. And some of the list have have sub menu. And on hover i want to display it. Firstly i am display it none and then on display it on hover but it is not displaying.
#menu {
width: 15%;
height: 100%;
background: #424242;
color: white;
float: left;
}
#menu ul {
margin: 0;
padding: 0;
}
#menu li {
list-style: none;
font-size: 20px;
padding: 15px 20px;
cursor: pointer;
}
#menu li:hover {
background-color: #90CAF9;
}
#menu li.active {
background-color: #2196F3;
}
#menu li ul {
display: none;
}
#menu li:hover ul {
display: block;
position: absolute;
left:100%
}
<div id="menu">
<ul>
<li onClick="Dashboard();">Dashboard</li>
<li>Employee >
<ul>
<li>Add Employee</li>
<li>Employee View</li>
</ul>
</li>
<li>Leave</li>
<li>Salary</li>
<li>Change Password</li>
</ul>
</div>

Answer 1

#menu {
width: 150px;
height: 100%;
background: #424242;
color: white;
float: left;
}
#menu ul {
margin: 0;
padding: 0;
}
#menu li {
list-style: none;
font-size: 20px;
padding: 15px 20px;
cursor: pointer;
}
#menu li:hover {
background-color: #90CAF9;
}
#menu li.active {
background-color: #2196F3;
}
#menu ul li ul {
display: none;
}
#menu ul li.submenu {
position: relative
}
#menu ul li.submenu ul {
position: absolute;
left: 150px;
width: 200px;
top: 0;
background: #333
}
#menu ul li.submenu:hover ul {
display: inline-block
}
<div id="menu">
<ul>
<li onClick="Dashboard();">Dashboard</li>
<li class="submenu">Employee >
<ul>
<li>Add Employee</li>
<li>Employee View</li>
</ul>
</li>
<li>Leave</li>
<li class="submenu">Salary
<ul>
<li>Add Employee</li>
<li>Employee View</li>
</ul>
</li>
<li>Change Password</li>
</ul>
</div>
Also Add .submenu class to submenu dropdown parent li.