Check for a key in the query data that was part of the HTTP request
ns_queryexists looks in the query data for the specified key. If the key exists, 1 is returned; otherwise 0 is returned. The key is interpreted in a case insensitive manner.
ns_register_proc POST /queryexiststest queryexiststest proc queryexiststest { } { if [ns_queryexists name] { # process the form } else { ns_returnerror 400 "need to supply your name in the form" } } ;# queryexiststest