JSFiddle - React, Tailwind, and code Playground

HTML

<form id="searchform" name="searchform" method="get" action="">
		
<div class="selector">
	<div class="selector-label">Show available</div>
	<select name="type" class="require_one">
		<option value="">* Please select</option>
		<option value="rooms">rooms</option>
		<option value="houses">houses</option>
	</select>
</div><!-- /.selector -->
			


<div class="selector">	
	<input class="btn" style="margin-top:-11px" id="submit" type="submit" value="Search" />
</div>

JavaScript

var $submitButton=$('.selector .btn');
var $selectors=$('.selector select.require_one');
$submitButton.attr('disabled','disabled');

$('.selector select.require_one').change(function(){
  var $empty=$selectors.filter(function() { return this.value == ""; });
   console.log("val %o    empty len %o",$(this).val(),$empty.length);
    if ( $selectors.filter(function() { return this.value == ""; }).length == $selectors.length ){
             $submitButton.attr('disabled','disabled');        
    } else
    {
        $submitButton.removeAttr('disabled');
    }
});

$('#submit').click(function() {
   $('#searchform').submit(); 
});