This command inserts new list values into existing user defined list type fields.
http://www.myserver.com/evj/ExtraView/ev_api.action?
user_id=username
&password=password
&statevar=add_udf_list
&udf_name=my_field
&udf_values=val
To add more than one list value with a single API command, you need to have encoded the tab character separator in your API command.
This example adds xxx, yyy and zzz as values to a UDF named my_field.
http://www.myserver.com/evj/ExtraView/ev_api.action?
user_id=username
&password=password
&STATEVAR=add_udf_list
&UDF_NAME=my_field
&UDF_VALUES=xxx%09yyy%09zzz
