Rule that reacts when user goes to checkout

{ "rules_test" : {
    "LABEL" : "test",
    "PLUGIN" : "reaction rule",
    "REQUIRES" : [ "rules", "entity" ],
    "ON" : [ "commerce_order_update" ],
    "IF" : [
      { "data_is" : { "data" : [ "commerce-order:status" ], "value" : "checkout_checkout" } }
    ],
    "DO" : [
      { "drupal_message" : { "message" : "You have gone from Shopping Cart to Checking Out! WOOHOO!" } }
    ]
  }
}