In the locals window we need to show users the eval errors. We should do this in the same way C# does via a message box. Currently we just do nothing and leave the value as is.
Example:
```
function foo() {
var x = 1;
}
```
Now try to change x in the locals window
```
x = Blah
```
We should show the same error message you would see if you did this in the immediate window
```
ReferenceError: blah is not defined
```
Example:
```
function foo() {
var x = 1;
}
```
Now try to change x in the locals window
```
x = Blah
```
We should show the same error message you would see if you did this in the immediate window
```
ReferenceError: blah is not defined
```