It would depend on your server and your variable names.
As I have told you over at least 3 different times over skype, you don't need to be checking the teleBlockLength, that should be done in the teleport code.
You also need to understand what each of the following methods do:http://docs.oracle.com/javase/7/docs/api/java/lang/String.html
With your current code, the command expects the word to be longer than "trade". It expects that there will be something
after the word. It doesn't expect anything specific, but it does expect something. So a space, a number, a letter, literally anything.
If your donators have the boolean 'isDonator' set to true in their accounts, then you could do something like:
c.getPA().startTeleport(2605, 3097, 0, "modern");
c.sendMessage("You teleport to the trade area.");
and then only players with "isDonator" set to true will be able to use the trade command.