get variable under Network tab on browser using jQuery [duplicate]

I have a simple search submission form on one page with the following code…

<form id="FormSearch" method="POST" class="customform" action="forum-search.php">
    <label for="SearchWord" class="topLabel SearchPage">Search Forum
        <input type="text" name="SearchWord" id="SearchWord" placeholder="Search...">
    </label>
</form>

When a search term is submitted, you are sent to forum-search.php which is where I want jQuery or JavaScript to handle the results of the search.
Under the network tab on my browser, I can see SearchWord: ‘word searched’ How can I use jQuery or JavaScript to access the SearchWord variable?