Register Button not working

[kennyrkun]

www.mehsworld.com running version 1.8.7

On my forums (www.mehsworld.com) the "Submit Registration!" button doesn't work on any of my themes, even the default one. the button to refresh the recaptcha doesn't work either. Any ideas why this is happening and how to fix it?

also, on the register page, searching for a just says loading failed.

[.m.]

run file verification tool from below location. what does it report ?
admin panel >> tools & maintenance >> file verification
ignore reported images & ignore files reported from install folder & its sub-folders

[kennyrkun]

run file verification tool from below location. what does it report ?
admin panel >> tools & maintenance >> file verification
ignore reported images & ignore files reported from install folder & its sub-folders

This is what it returned 

http://pastebin.com/31vETxgy (because it paste good on here)

[.m.]

download MyBB 1.8.7 pack again and replace below files (total 9 files)
~/xmlhttp.php
~/search.php

~/inc/class_parser.php

~/inc/cachehandlers/eaccelerator.php
~/inc/cachehandlers/xcache.php
~/inc/cachehandlers/apc.php
~/inc/cachehandlers/interface.php
~/inc/cachehandlers/memcached.php
~/inc/cachehandlers/memcache.php

after replacing above files check if the registration process works.