VLOOKUP Based on Date of Most Recent Data Entry

I'm trying to generate a VLOOKUP formula and neeed your guy's help:

Number Project Date Started Date Ended
123456 ABC 6/1/2014 6/10/2014
123456 ABCD 6/10/2014

I'm working with data similar to above and sometimes will have data entered twiced for a person. (ex. 123456). The difference between the two is that the person is on a different project during a time period. A person can only be on one project at a time.

I am able to determine the project that the person is currently working on based on whether the "Date Ended" cell is blank.

I was wondering if there is a VLOOKUP that will lookup the data based on the Person (123456) and look to find the most recent project that the person is on based on the date started/ended. My return value would be ABCD.