this script is right? check and unckeck all

<script language="JavaScript">
<!--

function setCheckboxes(the_form, do_check) {

var elts = (typeof(document.forms[the_form].elements['ID[]']) != 'undefined')

? document.forms[the_form].elements['ID[]']

: (typeof(document.forms[the_form].elements['ID[]']) != 'undefined')

? document.forms[the_form].elements['ID[]']

: document.forms[the_form].elements['ID[]'];

var elts_cnt = (typeof(elts.length) != 'undefined')

? elts.length

: 0;

if (elts_cnt) {

for (var i = 0; i < elts_cnt; i++) {

elts.checked = do_check;

} // end for

} else {

elts.checked = do_check;

} // end if... else

return true;

}

// --></script>

END;


<a href=# onClick="setCheckboxes('masssell',true); return false;">Check All</a> |
<a href=# onClick="setCheckboxes('masssell',false); return false;">Uncheck All</a>

 

Whats with all the ternary operators that aren't even doing anything?

 

I dont know java script i just got script from somewhere and its not working