CSS And HTML Validation
This is always the first step for me. I make sure that I am working with valid html and styling. Visit the W3C CSS Validation Service and check your style sheet. This page is pretty self-explanatory. The following is the result you are looking for:
The next step is to visit the W3C Markup Validation page. The following is the result you want form the validator:
Please visit page 3 for more.