value of select box

i have a select box

on one of the options it has an on click option to check all check boxes on page

problem is that when this code runs it takes the value of the check box and replaces it with a javascript value..

i dont want this

see code

JavaScript Code top of page

<script language="javascript" type="text/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>

Code (markup):

<form name="userRights" method="post" action="nextPage.asp">	
<select name="adminLevel">
	<option value="0">Please Select</option>
	<option  onClick="this.value=check(document.userRights)" value="4">Admin of site </option>
	<option value="3">General User of site </option>
</select>

Code (markup):

on the next page if i do a response.write of adminLevel when i have selected the 'Admin of Site' option it writes the value Check all or Uncheck all and not 4 what i want it to.

Please advise...

Thanks

 

cant understand proper.What u want please explain again.

Do u have problem in check Or Uncheck All??