Is there such a thing as a tool which will help in creating the CSS code to make rounded cornered frames around modules? (to be used in conjunction with "module suffixes")

If not, can you point me in the right direction to learn how to do this (tutorial) ?

I have this code for the CSS:

div.module_menu { background: url(../images/bottomright.png) 100% 100% no-repeat; }

div.module_menu div { background: url(../images/bottomleft.png) 0 100% no-repeat; }

div.module_menu div div { background: url(../images/topright.png) 100% 0 no-repeat; }

div.module_menu div div div { background: url(../images/topleft.png) 0 0 no-repeat; }

How do I now do the images?