Вы можете определить это так с помощью свойства css sticky:
$('#sticky').bind('click', function(event) {
//do what you want
var x = document.getElementById("industries_served");
var option = document.createElement("option");
option.text = prompt("Please enter a new value", "Florida");
x.add(option);
});
* {
font-size: 16px;
}
#sticky {
position: -webkit-sticky;
/* Safari */
position: sticky;
bottom: 0;
border-top: .5px solid;
color: blue;
}
select {
border: none;
}
#wrapper {
border: 1px solid;
width: fit-content;
margin: auto;
/* just here to center the div*/
}
.dropbtn {
background-color: #4CAF50;
color: white;
padding: 16px;
border: none;
}
.dropdown {
position: relative;
display: inline-block;
}
.dropdown-content {
display: none;
position: absolute;
z-index: 1;
}
#industries_served option:hover {
background-color: #ddd;
}
#sticky:hover {
background-color: #ddd;
}
.dropdown:hover .dropdown-content {
display: block;
}
.dropdown:hover .dropbtn {
background-color: #3e8e41;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class="dropdown">
<button class="dropbtn">Dropdown</button>
<div class="dropdown-content">
<div id="wrapper">
<select class="ui fluid search dropdown" id="industries_served" name="industries_served" multiple="">
<option value="">State</option>
<option value="AL">Alabama</option>
<option value="AK">Alaska</option>
<option value="AZ">Arizona</option>
<option value="AR">Arkansas</option>
<option value="AR">New Mexico</option>
<option value="AR">New York</option>
<option value="AR">???</option>
</select>
<div id="sticky">+ Add more</div>
</div>
</div>
</div>