Hi there!!! I want to access a bidimensional array in a form from javaScript, but I do not know how to do that. this is the form

Code:
<td><input   type="text" name="tn['.$elem['id'].'][]" value="'.$elem['name'].'" />  </td>
As you can see, it is PHP code that generates several input form. What I want to get is the array "tn" in JavaScript, because I need to check that the text is not empty

thanks a lot!