Why wont my hotmail open emails?

I have tried it on Firefox, Chrome and Internet Explorer, and it happens with all of them. I can sign on fine, and I can get to the list of all my emails in my inbox and junk box and everything, but I when I click on them, nothing happens? Recently, I have found that with I cant check out my online contacts any more either. If anyone could tell me how I can fix this, it would be greatly appreciated!