... a discussion of field substitutions (aka variable fields) will eventually get written...

Substitutions:
<input type="hidden" name="fullname" value="[lastname], [firstname]">

... a discussion of "if" logic will eventually fill in here...
[if,field1]if field1 is nonblank then the text stays[endif]
[if;field1]if field1is blank then this text stays[endif]
(or is it the other way around???)

as in:
<input type="hidden" name="option1" value="[if,checkbox]yes[endif][if;checkbox]no[endif]">

FORMMAIL.ASP does convert YES/NO properly for yes/no field types

[if,field][endif] blank/non-blank fields processing [if,list]yes[endif][if;list]no[endif]

Available System Variables:
DATE
TIME
TIMESTAMP,
REMOTE_HOST,
REMOTE_ADDR,
REMOTE_USER,
HTTP_USER_AGENT,
DOMAIN_NAME
HTTP_REFERER

as in:
<input type="hidden" name="source" value="[domain_name]">

FORMMAIL.US automatically updates database fields named:
"timestamp"
"remote_computer_name"
"browser_type"