ลองดูครับ มั่วๆ
function cp_module_pcontent_post_content($content){
global $post;
global $cp_module_pcontent_hide;
if(!in_array($post->ID,(array)$cp_module_pcontent_hide)){
return $content;
}
$c = '<div>';
$c .= '<p>' . get_option('cp_module_pcontent_text_pay') . '</p>';
$c .= apply_filters('cp_module_pcontent_post_content_'.$post->ID, '');
$c .= '<form method="post">';
$c .= '<input type="hidden" name="cp_module_pcontent_pay" value="'.$post->ID.'" />';
$c .= '<p><input type="submit" value="'.get_option('cp_module_pcontent_text_button').'" /></p>';
$c .= '</form>';
$c .= '</div>';