public static function plugin_activation()
{
//check version of WP current
if (version_compare($GLOBALS['wp_version'], J_CHAT_MINIMUM_VERSION, '<')) {
die('Please upgrade your wordpress minium is ' . J_CHAT_MINIMUM_VERSION);
}
//check version of plugin
$plugin_version = get_option('j_chat_version');
if (!$plugin_version) {
add_option('j_chat_version', J_CHAT_VERSION);
//create table
jChatMessage::createTable();
} else {
update_option('j_chat_version', J_CHAT_VERSION);
}
}
