Description: Set a value to effectAllowed attribute
Test Result Test Assertion
Manual Test passes if if the word "PASS" appears to the left after following the steps below.
Steps:
  1. Drag the blue image and enter the green box

http://dev.w3.org/html5/spec/dnd.html#datatransfer

On setting, if the new value is one of "none", "copy", "copyLink", "copyMove", "link", "linkMove", "move", "all", or "uninitialized", then the attribute's current value must be set to the new value.