check if input checkbox checked not working

check if input checkbox checked not working

form :
<label for="sitecheck">
<span style="font-weight:bold;">ñâåø àúø æîðéú:</span>
</label>
<input name="sitecheck" type="checkbox" id="sitecheck"
onClick="validateSitec();" <?php if($data['sclosed'] == 'true'){echo
'checked = "checked"';}; ?> /><span style="font-weight:bold;">ñâåø àúø
åøùåí äåãòä æîðéú</span><br>
<input type="text" name="closedmsg" id="closedmsg"
style="width:440px;height:120px;<?php if($data['sclosed'] == 'true'){echo
'';}else{ echo 'display:none;'; }; ?>" value="<?php echo
$data['csitemsg']; ?>" /><span id="sitemsg_error"></span>
php :
if(isset($_POST['sitecheck']))
{
$sitecheck = 'true';
}else{
$sitecheck = 'false';
}
any idea why its not working ? i trying to determine if checked or not and
update on Database.. anyidea why its alwys true even if i uncheck?
EDIT :
fixed by my own was ajax post wrong , i should val the checked box like
that :
var sitecheck = $('#sitecheck').is(':checked') ? $('#sitecheck').val()
: '' ;
so now working thanks.