Shell Programming and Scripting

I'm using redhat and have an odd issue with a nested ssh call.

Code:

ssh -i ~/.ssh/transfer-key -q transfer@fserver1 [[ -f /home/S/outbox/complete ]] 
&& ssh -i ~/.ssh/transfer-key transfer@fserver1 "ssh -i ~/.ssh/sftp-key sftpin@10.0.0.1 [[ ! -f /datain/complete]]" 
&& ssh -i ~/.ssh/transfer-key transfer@fserver1 "scp -i ~/.ssh/sftp-key /home/S/outbox/* sftpin@10.0.0.1:/datain" 
&& ssh -i ~/.ssh/transfer-key transfer@server1 "rm /home/S/outbox/*"

what this is doing is checking if a complete file is in an outbox, if so, ssh to a transfer server, executing a second ssh and checking if a file is 'not' present on the destination and if no, sending the files. I'm restricted to which ids and servers can be used, hence this convoluted method.

I'm getting a syntax error on the part where I'm checking if the file doesn't exist on the target.

Code:

ksh: syntax error at line 1: `[[' unmatched

Any ideas how to check this in an embedded ssh call?

Thanks in advance

---------- Post updated at 10:19 AM ---------- Previous update was at 10:13 AM ----------

doh... missed a space at the end before ]]
only when I posted it here was it obvious.