In the instructions.html. It is a little unclear as to the minimum fields necessary to search.
The user should be able to select the origin and destination of flights, and the display should update to show only flights that satisfy those criteria. The user must be able to describe enter the string value "any" for the origin, destination, or both, so as to implement a wildcard-like feature.
Is one statement, which makes you need at least origin and destination a must.
Then it also states
For example, the following argument string would select all records describing flights by the SpeedyAir carrier that originate in San Francisco.
"Carrier='SpeedyAir',Origin='SFO'"
In this example Carrier is also there. Here is where the confusion comes in. In the first statement carrier is not included, but here it is.
My take is to also include carrier.
Mark