rounded corners for post background

Hi all. got a little problem i know most of you could help me with

I made my skin and it has all rounded corners but in the post box its still not rounded
can some one help me out here please

my post box screen shot


much thanks for any help you can give

Ape

Code:

span.corners-top {
background-image: url(http://2img.net/i/fa/fdf3/corners_left.png);
background-position: 0 0;
margin: 0 -5px;
}


Add that to your CSS.

Code:

span.corners-top span {
background-image: url(http://2img.net/i/fa/fdf3/corners_right.png);
background-position: 100% 0;
}

And that too.

that only changes the top is there any code that will do the bottom aswell

Code:

span.corners-bottom {
background-image: url(http://2img.net/i/fa/fdf3/corners_left.png);
background-position: 0 100%;
clear: both;
margin: 0 -5px;
}

Code:

span.corners-bottom, span.corners-bottom span, span.corners-top, span.corners-top span {
background-repeat: no-repeat;
display: block;
font-size: 1px;
height: 5px;
line-height: 1px;
}

bottom right is still not rounded

EDIT:
can i not do it with out the image and do it with this sort of code

Code:

border-radius: 10px;
-webkit-border-radius: 10px;
-o-border-radius: 10px;
-khtml-border-radius: 10px;

Code:

span.corners-bottom span {
background-image: url(http://2img.net/i/fa/fdf3/corners_right.png);
background-position: 100% 100%;
}

solved with thanks