Hai solo da cambiare le misure a tuo piacere
codice:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Documento senza titolo</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<style type="text/css">
.div-1 {
border: none;
height: 19px;
position: relative;
text-align: left;
width: 687px;
}
.div-1-1 {
border: none;
height: 19px;
left: 0px;
line-height: 19px;
padding: 0px;
position: absolute;
text-align: center;
top: 0px;
width: 343px;
}
.div-1-2 {
border: none;
height: 19px;
left: 343px;
line-height: 19px;
padding: 0px;
position: absolute;
text-align: center;
top: 0px;
width: 344px;
}
</style>
</head>
<body>
<div class="div-1">
<div align="center" class="div-1-1">Qui inserisci il calcolatore</div>
<div align="center" class="div-1-2">Qui inserisci l'iframe</div>
</div>
</body>
</html>