 on
   whether or not the field was found. <br>&nbsp;&nbsp;&nbsp;<span class="type">[logical, optional]</span></td>
</tr>
</table>
</dd>
<br>
</dl>
</li>
<li>
<a name="read_data"></a>
<h4>read_data</h4>
<pre>
<b>call read_data </b>(filename,fieldname,data,domain,timelevel)</pre>
<dl>
<dt>
<b>DESCRIPTION</b>
</dt>
<dd>   This routine performs reading "fieldname" stored in "filename". The data values of fieldname
   will be stored in "data" at the end of this routine. For fieldname with multiple timelevel
   