I am trying to replace the drop downs on this form with checkboxes using something like this:

<div class="form-check form-check-inline">
<label class="form-check-label">
<input class="form-check-input" type="checkbox" id="inlineCheckbox1" value="option1"> 1
</label>
</div>

In this form page:

<!DOCTYPE html>
<html lang="en">
<head>
<title>Albany, NY Real Estate Homes for Sale</title>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta.2/css/bootstrap.min.css" integrity="sha384-PsH8R72JQ3SOdhVi3uxftmaW6Vc51MKb0q5P2rRUpPvrszuE4W 1povHYgTpBfshb" crossorigin="anonymous">

</head>
<body>
<script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.3/umd/popper.min.js" integrity="sha384-vFJXuSJphROIrBnz7yo7oB41mKfc8JzQZiCq4NCceLEaO4IHwi cKwpJf9c9IpFgh" crossorigin="anonymous"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta.2/js/bootstrap.min.js" integrity="sha384-alpBpkh1PFOepccYVYDB4do5UnbKysX5WZXm3XxPqe5iKTfUKj NkCk9SaVuEZflJ" crossorigin="anonymous"></script>


<form action="/cgi-bin/mailer.pl" method="post" name="FirstLookForm" id="FirstLookForm" >
<input type="hidden" name="subject" value="First-Look-1F-Albany">
<input type="hidden" name="recipient" value="1">
<input type="hidden" name="required" value="email">
<input type="hidden" name="redirect" value="../thankyou.html">
<h4>Essentials</h4>

<form role="form" class="form-horizontal">

<div class="row">
<div class="col-xs-12 col-md-4">
<form role="form">
<div class="form-group">
<label for="sel2">Minimum Bedrooms:</label>
<select multiple class="form-control" name="Bedrooms" id="sel2">
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
<option value="5">5</option>
</select>
</div>
</div>

</form>

</body>
</html>

(page stripped of everything but relevant HTML)

This is the form action:

<form action="/cgi-bin/mailer.pl" method="post" name="FirstLookForm" id="FirstLookForm" >
<input type="hidden" name="subject" value="First-Look-1F-Albany">
<input type="hidden" name="recipient" value="1">
<input type="hidden" name="required" value="email">

I have tried every substitution but the input won't post. Any help would be greatly appreciated.