[xwiki-users] where does the actual registration happen?

Dear All I have inserted a captcha field into our registration page. It validates correctly. However the user is still registered even if the code is incorrectly entered. I have tried to find the part within the code which actaully does the registering once the fields are correctly filled in. I could then put this in an if statement which depends on $reg and the captcha field. However I can't find it. Please, please, please can someone now just help me finish off. I attach a short version of the code I have. ## declare the plugin #set($captchaPlugin = $xwiki.jcaptcha) ##verify captcha ##call the verifyCaptcha #if($captchaPlugin.verifyCaptcha("edit")) <h2>captcha correct</h2> #else <h2>captcha wrong</h2> #end #if(!$reg||$reg<0 ) <p>Welcome ......</p> #end #if($reg && $reg<=0) #if($reg==-2) #error("$msg.get('core.register.passwordMismatch')") #elseif($reg==-3) #error("$msg.get('core.register.userAlreadyExists')") #elseif($reg==-4) #error("$msg.get('core.register.invalidUsername')") #elseif($reg==-8) #error("$msg.get('core.register.userAlreadyExists')") #else #error("$msg.get('core.register.registerFailed', [$reg])") #end #elseif($reg) #set($xwname = "XWiki.${request.xwikiname}") #info("$msg.get('core.register.successful', [$xwiki.getUserName($xwname), $request.xwikiname])") #end #if(!$reg||$reg<0) <form id="register" action="verifyCaptcha" method="post"> <div> #set($captchaPlugin = $xwiki.jcaptcha) <input type="hidden" name="template" value="XWiki.XWikiUserTemplate" /> <input type="hidden" name="register" value="1"/> #set($class = $xwiki.getClass("XWiki.XWikiUsers")) #set($obj = $class.newObject()) #set($serverobj = $class.newObject()) #set($discard = $doc.use("XWiki.XWikiUsers")) #if($request.register_first_name) $doc.set("first_name", $request.register_first_name) #end #if($request.register_last_name) $doc.set("last_name", $request.register_last_name) #end <dl> ##username <dt>$msg.get("core.register.username")</dt> <dd><input name="xwikiname" type="text" size="20" onfocus=" prepareName(document.forms.register);" /></dd> ##password ##lots of form fields here #if ($captchaPlugin) $captchaPlugin.displayCaptcha("edit","register_captcha") #end <span class="buttonwrapper"><input type="submit" value="$msg.get("core.register.submit")"/></span></div> </form> #end