How to add a Search button?

How to add a Search button?

I have a search input on my site that works by clicking 'Enter', but for
some reason I can't figure out how to simply implement a clickable
'Search' button (image button) to go along next to it. How do I do this?
Here is my search code:
<div id="searchwrap">
<li id="search">
<form id="search-form" name="search" action="/products" method="get">
<input id="search-input" name="search" type="text">
</form>
</li></div>