pretty tough,
i've done this but getting syntax errors
echo $this->cartClass->displayButton(JText::_('HIKA_REGISTER'),'register',$this->params,'','if(hikashopCheckChangeForm(\'register\',\''.$this->form_name.'\') && hikashopCheckChangeForm(\'user\',\''.$this->form_name.'\') && hikashopCheckChangeForm(\'address\',\''.$this->form_name.'\')'.$additional_check.'){ var button = document.getElementById(\'login_view_action\'); if(button) button.value=\'register\'; document.'.$this->form_name.'.submit(); document.getElementById('register_name').value = address_firstname.value + ' ' + address_lastname.value; } return false;');
i'm not great with JS any help highly appreciated