fix validator is undefined error code 0

i have several online designer forms for numberplate making on line basically these designers allow the customer to go to a page on my website were they can then enter detils of there vehicle registration then add logos and fonts ect to make ther eown personalised numberplates which we then produce and send to them .how ever the website has not been in use for a few years and were back at it now and nothing is working corectly we need them fixed the main page were they design everything seems ok but the checkout page shows the following errors Webpage error details User Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trident/4.0; .NET CLR 2.0.50727; .NET4.0C) Timestamp: Fri, 30 Mar 2012 08:24:45 UTC Message: 'Validator' is undefined Line: 331 Char: 2 Code: 0 URI: [login to view URL] can any one fix this for us or tell us what to do ?we find it a bit strange as every website designer we have and we have one for every type of plate sunstrip and more shows this error?.