<form method="POST"> 
       <input type="submit" class="but btn-reset" name="start" value="Start"> 
 </form> 
 <?php 
  foreach ($res as $key) { 
   echo '<form method="post"> 
           <input type="checkbox" name="form_start" value="Yes"> 
             <div class="func" onclick="myFunction()">' .$key['name'] . ' 
         </div></form>'; 
         if(isset($_POST['form_start']) &&  
         $_POST['form_start'] == 'Yes')  
       { 
         var_dump($_POST['form_start']); 
       } 
       else 
       { 
         var_dump($_POST['form_start']); 
       } 
 } 
 ?>   

   function myFunction() { 
     var x = document.getElementById("list"); 
     if (x.style.display === "none") { 
       x.style.display = "block"; 
     } else { 
       x.style.display = "none"; 
     } 
   }