AddNullCouponTest
waitForElementPresent link=Shopping Test Page
clickAndWait link=Shopping Test Page
clickAndWait link=Coupons
clickAndWait //input[@value='Add Coupon']
clickAndWait //input[@value='Save']
assertTextPresent You have entered invalid data. Please try again.
assertTextPresent Please enter a valid code.
clickAndWait link=Return to Full Page