Question for web designers

[CheatingSoi]

I'm working on a website for school and we are learning how to make responsive design. I can get everything to work fine in the browser window. But when I actually go to it on my phone. The background images are super stretched out. I have no idea how to fix this. I used browser view-port and anything so everything else looks find on the phone. Just the pictures. I'm not really sure how to explain this well but if anyone can help that would be great. Thanks.

 

[xdrako23x]

Would be great if you post picture of it ?

 

[ILOVETOPLAYNESGA]

I myself tend to use the width:100% and min-height:100% to quickly take care of background images if it does not matter what part they see.
However, I also give my background images if they are a single image a class of their own, with a z index of -1.... however, as xdrako23 said, a picture would help a lot.