Check All Button Script For Use In PHP

I'm using this bit of code I found online to do a check all/uncheck all button:

<SCRIPT LANGUAGE="JavaScript">
<!-- Begin
var checkflag = "false";
function check(field) {
if (checkflag == "false") {
for (i = 0; i < field.length; i++) {
field[i].checked = true;}
checkflag = "true";
return "Uncheck All"; }
else {
for (i = 0; i < field.length; i++) {
field[i].checked = false; }
checkflag = "false";
return "Check All"; }
}
// End -->
</script>

My problem is that if the input checkboxes look like this:

<input name="delChecked" type="checkbox" value="$itemcode">

The check all script works but PHP doesn't recognize that delChecked is an array. And if I do this...

<input name="delChecked[]" type="checkbox" value="$itemcode">

PHP reads delChecked as an array but the Javascript doesn't work.