Hi Bob,

it looks as though you evaluated this:

{InputField[Dynamic[x]], Dynamic[x]}

Next you seem to have entered "40" into the input field, then evaluated the output it produced, thus yielding another input field in your "Out" line. You don't actually have to do that, but you simply evaluate the original input, and when you enter something into the input field, it is assigned to x automatically. You never even hit "enter" from inside the input field. (There are actually ways to suppress output when a user accidentally does this, but the method isn't pretty and it may not be necessary if the input field is essentially inside a Manipulate.)

I'm not sure if you're aware that you don't actually need the second "Dynamic[x]". In the documentation, the Dynamic[x] is used to show that x does, in fact, change when you type something in the input field, but it doesn't have anything to do with setting the variable x. So usually you'd simply use this:

InputField[Dynamic[x]]

... which evaluates to an input field which assigns its contents to the variable x (or whatever you choose to call it). The input field really behaves like any other dynamic control element you might have in your code (sliders and setters and so forth).

For file names specifically though, you should take a look at FileNameSetter ( http://reference.wolfram.com/language/ref/FileNameSetter.html ), it's a lot more comfortable for most users than an input field.

I don't know exactly what kind of constructs Player Pro supports, some things may behave differently from a regular notebook. But I hope I could still help you a little.