unexpected error

dear UG,

I recently wrote a script that is supposed to perform an after submit function on a form, i have uploaded it but it keeps giving me a error when i try to use the form

'' you cannot submit this form due to an unexpected error''

What could be the cause of this error

thanks

your
ERP


Jaxer.load("uncheck");
//Call up all the variables
//Name all the fields involved.
// The function for the confirm should be provided



function savebutton()     {
        var nlapiGetFieldValue('custrecord_returned');
        var nlapiGetFieldValue('custrecord_date_returned');
           var nlapiSetFieldValue('Custrecord_available');
           var returnedmsg;
           var lentoutmsg;
           var notsavedmsg;