Meerdere rijen update...

$selectnieuws = mysql_query("SELECT * FROM nieuws WHERE site='de.site.nl' AND datum='2011-11-07' ORDER BY datum ASC")or die(mysql_error());
while($nieuws = mysql_fetch_assoc($selectnieuws)) 
{
//enz.
}

$selectnieuws = mysql_query("SELECT * FROM nieuws WHERE site='de.site.nl' AND datum='2011-11-07' ORDER BY datum ASC")or die(mysql_error());
while($nieuws = mysql_fetch_assoc($selectnieuws)) 
{
//enz.
}