PHP get multiple CheckBox value using form

<?php 
 $rtt = "";
    $chk = $_REQUEST['txtOwn'];
     if(empty($chk))
     {
  echo("You do not own anything.");
     }
     else
     {
  $N = count($chk);
  for($i=0; $i < $N; $i++)
  {
   $rtt = $rtt."  ,".$chk[$i];
  }
     } 
  
  echo $rtt;
?>


<form method="get">
 <input type="checkbox" name="txtOwn[]" value="AC" />AC<br />
 <input type="checkbox" name="txtOwn[]" value="Fridge" />Fridge<br />
 <input type="checkbox" name="txtOwn[]" value="TV" />TV<br />
 <input type="checkbox" name="txtOwn[]" value="Mobile" />Mobile<br />
 <input type="checkbox" name="txtOwn[]" value="Car" />Car<br />
 <input type="submit" >
 </form>