Shell Programming and Scripting

I am trying to initiate a ftp session from my shell script in the following way.
In my script, as per my requirements i am writing the required ftp commands to a file and then I am using this file to carry out the ftp process.

for example
temp.txt will contain
cd /home/user/mydir
append local.txt remote.txt

and then i am using the below command in my script to initiate the ftp.

cat test.txt | ftp -i $machine 2>$errname

The problem here is if the directory /home/user/mydir does not exist in the remote server then the file local.txt is appended to the file in /home/user (default directory pointed by the remote server)
Please suggest if there are any ways to check if the directory is present in the remote server before appending the file.

You can use the following if statement to check whether the directory exists or not in remote machine.

Code:

if[-n `ssh remotehost 'ls /home/user/mydir'`];then
echo "Directory exists";
else
echo "Directory not available";
fi

If the directory is present or not the message "Directory Exists" is displayed.
if the directory is not present, "mydir: A file or directory in the path name does not exist.' is displayed along with "Directory Exists" message.
Please let me know where im going wrong.

---------- Post updated at 11:50 PM ---------- Previous update was at 05:47 AM ----------

If the directory is present or not the message "Directory Exists" is displayed.
if the directory is not present, "mydir: A file or directory in the path name does not exist.' is displayed along with "Directory Exists" message.
Please let me know where im going wrong.