checkboxes and forms

[aron]

when the box is umchecked it emails me this

Name: unchecked
email: [e-mail]
Test Box:

and when it is checked it emails me this

Name: checked
email: [e-mail]
Test Box: checked

is their a way to make it not show Test Box: if it hasent been checked. So if it is unchecked it send me this

Name: unchecked
email: [e-mail]

sendmail script
<?
$body = "Name: $name\nemail: $email\nTest Box: $chk1\n";
mail("[e-mail]", "info request", $body,"From: $email" );
header( "Location: http://www.ermgroup.com.au/testphp/testemail.htm" );
?>

[TTT]

if($chk1 != "")

[intenz]

if($chk1)
     $body = "Name: $name\nemail: $email\nTest Box: $chk1\n";
else
     $body = "Name: $name\nemail: $email\n";
mail("[e-mail]", "info request", $body,"From: $email"); 
header("Location: [url]http://www.ermgroup.com.au/testphp/testemail.htm[/url]"); 

[aron]

this is just the example the real page has about 10 text fields and 7 checkboxes. Its an information form

how would i go about only printing thoes checkboxes that have been checked.

[TTT]

<form>
<input type="checkbox" name="chk[]" value="checked">
</form>

$listOfBoxes ="";
for($j=0;$j< count($chk);$j++)
{
$listOfBoxes = $listOfBoxes . "chk".$j. ":" . "$chk[$j]";
}