A lot of recent dell orders have come in without the cables for the monitor.   Here are your options: 

Use normal DVI cables:
http://amzn.to/1Q3IypR

You can use the display ports with normal DVI monitors with these adapters:
http://amzn.to/1Q3IEhn

OR if your monitors and computer both have display ports, you can get Display Port only cables:
http://amzn.to/1OlriMA