Javascript语法-我在做什么错？

Question

I am new to javascript. I have two documents--an old and a new--that I am comparing. However, I am getting a syntax error somewhere in the code below.
Somewhere in here, my code is blowing up. The error says "expression does not eval to a function." Any syntactic ideas of where I'm writing an incorrect statement?

if(userCtx.name != oldDoc.Document.attributeA) { 
        for (var key in oldDoc.Document)
        {
          if(newdoc.Document.hasOwnProperty('key')
          {
            if(oldDoc.Document[key] != newDoc.Document[key])
            {
               if(key === 'attributeB')
               {
                 return;
               }
               else
               {
                 throw(forbidden: 'Only admins may change this field.')
               }
            }
          }
        }
    } 

Answer 1

if(newdoc.Document.hasOwnProperty('key') <-- I am missing a )

Answer 2

To throw an object literal, replace the round brackets with curly brackets:

throw {
    forbidden: 'Only admins may change this field.'
};

Answer 3

Is the code you posted inside of a function definition? I've seen that error when defining functions that get passed as arguments to something else, and forgotten to wrap the function in parenthesis. For example:
"compare": "function(docA, docB) { ... }"
should be:
"compare": "(function(docA, docB) { ... })"

Answer 4

And possibly one more... Is this inside a function? If not you might be getting an error on the return;