validating checkbox

[Bruce Lee]

I am dynamically displaying some check boxs just like the one we see in the
mail box.

my requirement is i should see that there should be atleast one checkbox unselected. If not stop furthur execution.

how can i do this?

below is the ref code.

-----------
DO WHILE NOT objRds.EOF
response.write "<input type=checkbox name=movemsgid value='"
Response.write objRds("headingid") &"' >"&strName&""
objRds.MoveNext
LOOP
-------------
onsubmit chk()
-----------------
function chk()
{
here i need to check if all the checkboxes are checked or not?
i know some ways but then iam looking for a short way like is there any property which returns true or faslse if all checkboxs are checked or not.
something like
return document.myforum.checkox.selectedall
which returns true if all the checkboxes are selected
is there anything like that?
}

[jimfraser]

Pass the name of your checkbox elements to this function, it returns true if 1 or more is unchecked, false if they are all checked

function chk(nameOfCheckbox)
{
	oEls = document.getElementsByName(nameOfCheckbox);
	var i;
	for( i = 0; i < oEls.length && oEls[i].checked; i++ );

	return ( i < oEls.length );
}

[Bruce Lee]

working good thanks but small doubt
say name Of Checkbox is "curName"
when i called the function chk(curName) it didnot work
when i called the function chk('curName') it worked
How do i know when to use quotes and when i should not?

[jimfraser]

you should use quotes if you are passing the name directly.

And yeah, err, there is a bug
change
return ( i < oEls.length - 1 );
to
return ( i < oEls.length );

(original post edited to remove this bug)

[Bruce Lee]

if i need to send a numeric value as 1
then should i use chk(1) or chk('1') ?
any restrictions to numeric values?

[jimfraser]

No no - you pass the name of the checkbox element.

For example:
<input type="checkbox" name="city" value="New York">
<input type="checkbox" name="city" value="Los Angeles">
<input type="checkbox" name="city" value="Boston">
<input type="checkbox" name="city" value="Miami">
<input type="button" onclick="chk('city');" value="Check it">

[Bruce Lee]

checkbox prob solved.
i mean in general if i need to send numeric value.
then i should call add(1,2) than calling add('1','2') right?