2006 Ford Focus Power window for driver and passenger will

When I press the switch to roll down the driver window, nothing happens....The window will not roll down at all...Then the passenger window won't function either a couple of weeks later...
So now I have 2 windows closed and they won't roll down when I press the switch..
The 2 windows in the back are ok...
Any ideas, how to fix this?--I don't want to go the dealer to fix it,money is too tight now..so i would rather do it my self if it is a simple thing.Thank you..