How to create rounded corners that only the top?

I just want a round at the top of the course, but if I use the browser "Google Chrome" all the corners become rounded. What's the solution, friends?
This is my CSS:

.top_menu li a{
color:#FFFFFF;
text-decoration:none;
display:block;
padding:5px 20px 5px 20px;
background:#076cbe;
-moz-border-radius-topright:5px;
-moz-border-radius-topleft:5px;
-webkit-border-radius:5px;}

 

I think chrome uses the -webkit but I', not sure.

This will round the top corners by 5 px and keep the bottom corners normal:

border-radius: 5px 5px 0 0;
-moz-border-radius: 5px 5px 0 0;
-webkit-border-radius: 5px 5px 0 0;

 

Thanks style0, I've used it and succeeded.

 

Thanks for this man, I too wanted to round-edge one corner, works great.