_io_exit is called after all
   fields have been written by this subroutine. </dd>
<br>
<br>
<dt>
<b>INPUT</b>
</dt>
<dd>
<table border="0">
<tr>
<td valign="top" align="left"><tt>filename&nbsp;&nbsp;&nbsp;</tt></td><td>   File name <br>&nbsp;&nbsp;&nbsp;<span class="type">[character, dimension(*)]</span></td>
</tr>
<tr>
<td valign="top" align="left"><tt>fieldname&nbsp;&nbsp;&nbsp;</tt></td><td>   Field  name <br>&nbsp;&nbsp;&nbsp;<span class="type">[character, dimension(*)]</span></td>
</tr>
<tr>
<td valig