AddNullItemTest
waitForElementPresent link=Shopping Test Page
clickAtAndWait link=Shopping Test Page
clickAtAndWait //td[1]/a
clickAtAndWait //input[@value='Add Item']
clickAtAndWait //input[@value='Save']
assertTextPresent You have entered invalid data. Please try again.
assertTextPresent Please enter a valid item SKU.
clickAtAndWait link=Return to Full Page