How to assign default values in hook_form_alter

I need to move the 'Sticky' option to somewhere more visible on a form.

To do this, I'm using hook_form_alter as shown below.

My new field displays on screen, but never has the correct value (if I leave in the original sticky field, that *does* show values correctly).

So, what should I set the default value to in order to have the correct value (checked or unchecked) shown?

Thanks in advance.

Pete.

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function mymodule_form_alter(&$form, $form_state, $form_id) {

if (substr($form_id, -10)=='_node_form') {

unset($form['options']['sticky']); // remove the existing sticky field
// Create a new sticky field
$form['sticky']= Array
(
'#type' => 'checkbox',
'#title' => 'Sticky at top of lists - new field',
'#default_value' => $node->sticky,

);
}