Unless were talking thousands, then a CCJ is utterly pointless, you do realise you have to pay to get one issued anyway?
You also can't generally get an CCJ issued easily.
You have to first go through the small claims court, if they then failed to pay up you can then start the process of getting a CCJ against them which as far as I remember and I'm a little rusty at this, but costs at least £70 to get started. Then of course there's the enforcement of that via court appointed bailiffs which for small change would be a total waste of time for you and them both.
Just mark it as failed to pay and re-list it. If your hell bent on going this route, prepare to be laughed at by the judge.