( was unexpected at this time - batch script

Question

I\'m using the batch script below and get an error

( was unexpected at this time.

I know that the problem is in the first line but

Answer 1

As jamesdlin said, it's a problem with empty variables and also with delayedExpansion.
Then the solution is simple by replacing %isDefault% with !isDefault!, this works even if isDefault is empty.

setlocal EnableDelayedExpansion
IF [%1]==[] (
    :LOOP1
    SET /P isDefault=Value Missing, do you want to use default values [1,1,10,Local      Area Connection 2]?[y/n]
    IF !isDefault!==y (
        SET from=1
        SET step=1
        SET to=10
        SET lan="Local Area Connection 2"
        GOTO :USERLOOP
    )
    IF !isDefault!==n GOTO :END
    GOTO :LOOP1 
)