Button values are only submitted if the form is submitted by clicking the respective button. In your case the form is submitted in the onChange event of the "clocklater" or "clockyes" inputs.
You can submit it via a hidden field, or instead of submitting in the change event, you can use button type="submit" and trigger a button click in the mobiscroll's onSelect.
E.g. (for the "clocklater"):
$(function(){
$('#clocklater').mobiscroll().time({
theme: 'default',
display: 'modal',
mode: 'scroller',
setText: "Save",
cancelText: "Cancel",
headerText: "Available after",
timeFormat: 'HHii',
timeWheels: 'HHii',
stepMinute:10,
onSelect: function () {
submit = true;
$('[name=available]').val(2);
$('#later').click();
}
});
var submit;
$('#later').click(function(){
if (!submit) {
$('#clocklater').mobiscroll('show');
return false;
}
submit = false;
});
});
HTML changes:
<input name="clocklater" id="clocklater" class="i-txt" type='hidden' />
<div class='later button'>
<input id='later' name='available' type='submit' alt="later" value="later" />
</div>