New E6410 will not connect to a Digital Projector

I have a new Dell Latitude E6410 laptop from work with Windows 7.  I can not get the display to come up on the projector.  The projector is a NEC LT35.  I know it works and the cords are ok.  It was used last week in  training class.   Our IT department suggested lower the display resolution that did not help. Any Suggestions?