Ciao a tutti sono nuovo del html e css sto provando a realizzare un menù con delle immagini e bottoni.
Le immagini sono 6 e volevo metterle su 2 righe soltanto che non riesco questo è il mio codice html qualcuno mi può aiutare:
codice:
  
<!DOCTYPE html>
<html manifest="webapp.manifest">
<head>
	
	<link rel="stylesheet" href="styles/main.css">
    <script type="text/javascript" src="jlib/jquery-1.7.1.min.js"></script>
    <script type="text/javascript" src="scripts/storage.js"></script>    
    <script type="text/javascript" src="scripts/main.js"></script>
	<title>Sommario</title>
</head>
<body>

	<dl class="Riga1">
  		<dt>
		<input type="button" class="New" id="Nuovo" value=" " style="background-image:url('images/Nuovo.jpg')" 
			onclick=""></input>
		</dt>
		<dt>Nuovo</dt>	
	</dl>
	<dl class="Riga1">
  		<dt>
		<input type="button" class="LastDoc" id="UltimiDoc" value=" " style="background-image:url('images/UltimiDoc.jpg')" 
			onclick=""></input>
		</dt>
		<dt>Ultimi Documenti</dt>	
	</dl>
	<dl class="Riga1">
  		<dt>
	    <input type="button" class="SitCont" id="SituazContab" value=" " style="background-image:url('images/SitCont.jpg')" 
			onclick=""></input>
		</dt>
		<dt>Situazione Contabile</dt>	
	</dl>

	<dl class="Riga1">
  		<dt> <input type="button" class="Movim" id="Movimenti" value=" " style="background-image:url('images/Movim.jpg')" 
			onclick="">  </input>
		</dt>
		<dt>Movimenti</dt>	
	</dl>
	
	<dl class="Riga1">
		<dt> <input type="button" class="Statistic" id="Statistiche" value=" " style="background-image:url('images/Statistiche.jpg')" 
			onclick="">  </input>
		</dt>
		<dt>Statistiche</dt>	
	</dl>
	
	<dl class="Riga1">			
		<dt> <input type="button" class="Synchronize" id="Synchro" value=" " style="background-image:url('images/Syncro.jpg')"   
			 onclick="javascript:LanciaSyncro()"></input>
		</dt>
		<dt>Sincronizzazione</dt>	
	</dl>
	
	
	


</body>
</html>
e questo il css:
codice:
  
html,body, h1, form, fieldset, legend, ol, li 
{
	font-family:Georgia, "Times New Roman", Times, serif;
	margin: 0;
  	padding: 0;
  	text-align:center;
	margin:auto;	
}

body 
{
  background: #ffffff;
  color: #111111;
  font-family: Georgia, "Times New Roman", Times, serif;
  padding: 20px;
}

.New
{	
	background-repeat:no-repeat;
	background-position:center center;
	width:256px;height:256px;
	background-color: #D1D1D1;
}

.LastDoc
{	
	background-repeat:no-repeat;
	background-position:center center;
	width:256px;height:256px;
	background-color: #D1D1D1;
}

.SitCont
{	
	background-repeat:no-repeat;
	background-position:center center;
	width:256px;height:256px;
	background-color: #D1D1D1;
	
}

.Movim
{	
	background-repeat:no-repeat;
	background-position:center center;
	width:256px;height:256px;
	background-color: #D1D1D1;
}

.Statistic
{	
	background-repeat:no-repeat;
	background-position:center center;
	width:256px;height:256px;
	background-color: #D1D1D1;

 /*   vertical-align: top; */
    
}

.Synchronize
{	
	background-repeat:no-repeat;
	background-position:center center;
	width:256px;height:256px;
	background-color: #D1D1D1;
   /* font-size: 40px;
    vertical-align:  top;	*/
}

dl.Riga1
{
	border: 1px solid #000;
	background-color: #ddd;
	width: 266px;
	text-align: center;
	padding: 10px;
	float: left;
	margin-right: 1em;
	
}

.Riga1 dt 
{ 
	font-weight: bold; 
	font-size: 20px;
}

.Riga1 dt img
{
	border: 1px solid #000;
	width: 266px;
	height: 266px;
}

dl.Riga2
{
	border: 1px solid #000;
	background-color: #ddd;
	width: 266px;
	text-align: center;
	padding: 10px;
	float: left;
	margin-right: 1em;
}

.Riga2 dt 
{ 
	font-weight: bold; 
	font-size: 20px;
}

.Riga2 dt img
{
	border: 1px solid #000;
	width: 266px;
	height: 266px;
}
grazie