undefined procedure: elseif

I tried the following and it skips the rule completley, doesn't even log anything:

} elseif { [string tolower [HTTP::uri]] contains "StonesReg"} {
      log local0.
      HTTP::respond 301 "Location" "http://www.ameriquestmortgage.com/wwwmodules/stonessweeps.html?ad=1K" }

I also tried the following and it as well doesn't log anything and skips the rule

set my_uri [HTTP::uri]
if { [string tolower $my_uri] contains "StonesReg"} {
      log local0.
      HTTP::respond 301 "Location" "http://www.ameriquestmortgage.com/wwwmodules/stonessweeps.html?ad=1K"
    }

I must be doing something wrong here. All I want to do is take whatever combo of characters are passed through for the string stonesreg and redirect accordingly.

Thoughts?