This is not tested but I'm pretty sure it should work.
PHP Code:
public plugin_init()
{
register_plugin(PLUGIN, VERSION, AUTHOR);
register_event("Damage", "hook_Damage", "be", "2>0");
}
public hook_Damage(id)
{
new damage = read_data(2);
new name[32];
get_user_name(id, name, 31);
client_print(0, print_chat, "%s took %i damage.", name, damage);
}