500 error on Cloud Page

Here is the code on my cloud page. I'm a trying to change the status of a campaign member to Responded if they click on the RSVP button in an email. I am getting a 500 error. Does anyone see anything wrong with my code?

%%[var @FirstName, @CampaignMemberID, @statusset @FirstName = RequestParameter('First Name')set @CampaignMemberID = RequestParameter('CampaignMemberID')/* on page load */set @status = UpdateSingleSalesforceObject('CampaignMember',@CampaignMemberID,'Status','Responded')]%%%%First Name%%Thank you for registering for our event, looking forward to seeing you there.