How to set minimum purchase order amount

Question

When customer places an order, how to set minimum order amount?

i.e) Total amount of order not below than $500.

I know how to get total order amount. But I don't know where to place that code and where to check

   sOrderId = Mage::getSingleton('checkout/session')->getLastOrderId();
   $oOrder = Mage::getModel('sales/order')->load($sOrderId);
    if($oOrder >=$500)
    {
   .....
     }

If customer has purchased total less than $500, they won't allow to checkout at the cart.

Answer 1

Login as admin, then go to System->configuration, then select ‘Sales‘ from left Nav and click on ‘Minimum order amount‘. Then select Yes from Enable dropdown, enter Minimum order amount, enter message and also enter error message that will be shown whenever the order will be less than specified amount at the shopping cart.

Thanks.