Bash Script If null evaluating as false when true

Bash Script If null evaluating as false when true

I've run into my second hurdle in my journey into shell scripting. I
cannot seem to get my if statement to evaluate as true for a null value. I
am trying to pass an argument to the script and have the script let me
know if I am missing the required variable. Unfortunately it keeps falling
through to the else statement, even though it should be evaluating the
variable as a null one. Here is the script:
if [ "$1" == "d" ]; then
if [ -n "$2" ]; then
echo "Please enter the local location of the files"
else
LOCAL=$2
scp -r -i ~/Dropbox/Business/aws/first.pem $LOCAL
ubuntu@54.XXX.194.202:~/test/
fi
else
scp -r -i ~/Dropbox/Business/aws/first.pem
~/Dropbox/Business/aws/files/binaryhustle/
ubuntu@54.XXX.194.202:~/test/
fi
Here is the command I am running to execute the script:` bash copyfile.sh d
The response I get is:
usage: scp [-12346BCpqrv] [-c cipher] [-F ssh_config] [-i identity_file]
[-l limit] [-o ssh_option] [-P port] [-S program] [[user@]host1:]file1 ...
[[user@]host2:]file2 `