Paint a rectangle

How can I paint in a web page a rectangle with rounded corners?

Thank youI created a custom ASP.NET server control to allow for this... See:

Introducing the RoundedCorner Web Control
http://aspnet.4guysfromrolla.com/articles/072804-1.aspx

-and-

Improving the RoundedCorners Web Control
http://aspnet.4guysfromrolla.com/articles/081104-1.aspx

hth