I have the following custom meta-box, which works to list a post type, I simply want to allow multiple values to be selected but cannot get it to work, it appears if I tell the select to store multiple and set the name to be an array Wordpress does not store any value.
After hours of trying with different meta-boxes I realise I must be close but am clearly missing something.
Many thanks in advance.
I'm not sure if select multiple value from the select box is what you want, but from a quick look at you code i would say you should put
<select name="'.$field['id'].'[]" id="'.$field['id'].'">
instead of
<select name="'.$field['id'].'" id="'.$field['id'].'">
since you want a multiple select. This is then a html problem, not a WP related.
Try to use this plugin http://wordpress.org/extend/plugins/advanced-custom-fields/ I guess it will fit main part of your needs. Export to PHP in code available.
