Placing the standard property after the proprietary ones will result in the standardized property being applied in place of the proprietary one as web-browsers update to support the standard properties. I’m not sure if that’s the only reason for this best practice, but it’s at least one good reason to do so.

and your css something like this

a.roundedbigbox{
width:300px; //width of your ad
height:250px; //height of your ad
display:block;
border: 2px solid black;
border-radius: 30px;
-moz-border-radius: 30px;
-khtml-border-radius: 30px;
-webkit-border-radius: 30px;
text-indent:-10000em; // to hide your text version of the link
}

and you can change the border color for hover, visited etc.. like this

a.roundedbigbox:hover{
border: 2px solid red; // just changing the property that you want to change on the link state, everything else is inherited from the initial class styles
}

Hope that helps

- Dre