Good for you! 
Add
background-repeat:no-repeat;
Your finished page should not depend on a fixed height. The height should be determined by the content and, therefore, be flexible.
Can you post your code on a web site so we can see it?
If not, you can attach your HTML and CSS to a message (either in the body of the message or as attached file(s) ).
In other words, I would feel better about offering advice if I could see your code rather than having to guess.