I want to restriction shipping zone before checkout page.

1. I have set currencies zones
  1. US Dollar (default)
  2. Canadian Dollar


2. Zone Rates
Zone 1 Countries - US
Zone 2 Countries - CA

3. // CUSTOMIZE THIS SETTING FOR THE NUMBER OF ZONES NEEDED
$this->num_zones = 2;//includes/modules/shipping/zones.php
The above points i did.
4. The following options are uninstalled
Free Shipping Options
FREE SHIPPING!

How to restrict countries when register the user based on the shipping zones.

Please help.