My dell 942 printer won\'t print gives me a message to change the ink cartridges

[Bish_23]

I have a dell 942 printer that won't print anything. It keeps giving me the message to put in a ink cartridge on the left side. The cartridge has ink but neither the black or the color cartridge will click into place and stay that way. Anything I can do to remedy this or is the printer shot?

 

[PhilFrisbie]

Are you sure the cartridges are in the right slots, and that they are the correct numbers?