Hello, sorry to bother you all, and this is probably a rookie question

I am designing a web site, and i'm using css

I want to make some div's with curved edges, and this works with one div but i want to make the rest curved but this does not work.

Here's a snapshot: http://img103.imageshack.us/img103/3443/design2gd9.jpg -- the black box inside the green one is the problem

Here's what a want the div to look like: http://img66.imageshack.us/img66/8249/divjc2.jpg

here is the html code of the page:
Code:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>Untitled Document</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<link href="syle2.css" rel="stylesheet" type="text/css">
</head>

<body><div id="main"><div class="tlm"><div class="blm"><div class="brm"><div class="trm"><div id="logo">   </div><div id="lg-icon">   </div>
  <div id="lg-icon"><img src="home3.gif"></div><p>&nbsp;</p><div id="small-icons"><A HREF="somewhere.html"
onmouseover="document.sub_but.src='home2.gif'"
onmouseout="document.sub_but.src='home1.gif'">

<IMG SRC="home1.gif" BORDER="0" 
ALT="Move your mouse over me" NAME="sub_but">
</A></div>
  <p>&nbsp;</p>
  <p>&nbsp;</p>
  <p>&nbsp;</p>
  <p>&nbsp;</p>
  <div id="heading"> 
    <div class="t">
	  <div class="b">
		<div class="l">
		  <div class="r">
			<div class="blh">
			  <div class="brh">
				<div class="trh">
                  <div class="tlh">&nbsp;<div id="title"><div class="blt"><div class="brt"><div class="tlt"><div class="trt">Welcome</div></div></div></div></div>
      <p>&nbsp;</p>
      <p>&nbsp;</p>
      <p>&nbsp;</p>
      <p>&nbsp;</p>
      <p>&nbsp;</p>
      <p>&nbsp;</p>
      <p>&nbsp;</p>
    </div></div></div></div></div></div></div></div></div>
   
  <p>&nbsp;</p>
  <p>&nbsp;</p>
  <p>&nbsp;</p>
  <p>&nbsp;</p>
  


</div>
</body>
</html>
and here's the css

Code:
body {
	margin: 0px;
	padding: 0px;
	background-color: #383838;
	font-family: tahoma, arial, sans-serif;
	font-size: 8pt;
	background-image:url(body_bg.gif)
}

p, td, input, select, a {
	font-family: tahoma, arial, sans-serif;
	font-size: 8pt;
}

#main {background-color:#FFFFFF;
font-family:Verdana, Arial, Helvetica, sans-serif;
margin:20px 20px 20px 20px;}

.tlm {background-image:url(tlm.bmp); background-position: 0 0; background-repeat:no-repeat;}
.trm {background-image:url(trm.bmp); background-position: 100&#37; 0; background-repeat:no-repeat;}
.blm {background-image:url(blm.bmp); background-position: 0 100%; background-repeat:no-repeat;}
.brm {background-image:url(brm.bmp); background-position: 100% 100%; background-repeat:no-repeat;}

#logo {
	margin: auto;
	width: 202px;
	height: 160px;
	background-image: url(logo.gif)
}
#lg-icon {float:left; margin-left: 30px; width:auto; height:auto; background-image: url(home3.gif); background-repeat:no-repeat;}

#small-icons {float:right; margin-right: 100px; width:auto; height:auto;}

#heading {height:300px; width:auto; margin: 30px 30px 30px 30px; font-family:Arial, Helvetica, sans-serif; background-color:#FFFFFF;}

#title {width: 98%;height:20px; background-color:#000000;font-color: #ffffff; margin: 0 10px 10px 10px;}


.tlh {background:url(tlh.gif); background-position: 0% 0%; background-repeat:no-repeat;}
.trh {background:url(trh.gif); background-position: 100% 0%; background-repeat:no-repeat;}
.blh {background:url(blh.gif); background-position: 0 100%; background-repeat:no-repeat;}
.brh {background:url(brh.gif); background-position: 100% 100%; background-repeat:no-repeat;}

.t {background: url(dot.gif) 0 0 repeat-x;}
.b {background: url(dot.gif) 0 100% repeat-x}
.l {background: url(dot.gif) 0 0 repeat-y}
.r {background: url(dot.gif) 100% 0 repeat-y}

.cbl {background: url(cbl.png) 0 100% no-repeat #e9eef1; width: 100%}
.cbr {background: url(cbr.png) 100% 100% no-repeat}
.ctl {background: url(ctl.png) 0 0 no-repeat}
.ctr {background: url(ctr.png) 100% 0 no-repeat; padding:10px}

.blt {background:url(blt.bmp)  0 100% no-repeat;}
.brt {background:url(brt.bmp) 100% 100% no-repeat;}
.tlt {background:url(tlt.bmp) 0 0 no-repeat;}
.trt {background:url(trt.bmp) 100% 0 no-repeat;} 


 .bl {background: url(bl.gif) 0 100% no-repeat #e68200; width: 20em}
.br {background: url(br.gif) 100% 100% no-repeat}
.tl {background: url(tl.gif) 0 0 no-repeat}
.tr {background: url(tr.gif) 100% 0 no-repeat; padding:10px}
.clear {font-size: 1px; height: 1px}