devname is defined by

<dtml-let devname="this().getId()">

in earlier code
domain should be hard coded into my form action.
cmdb_field_value is the user input in the text box.

insertintocmdb is a z sql method, expecting 3 arguments.  cmdb_name, cmdb_field and cmdb_field_value


<FORM ACTION="insertintocmdb" METHOD="POST">
 <INPUT NAME="cmdb_field_value" TYPE="submit" VALUE="update cmdb">
 <input type="form" value="<dtml-var domain>" />
 <input type="hidden" name="cmdb_field" value="domain" />
 <input type="hidden" name="cmdb_name" value=devname />

</FORM>