Hello,
No. CJT cannot do that for you.
CJT Code-Block can be just assigned to a request (page, post, URL, etc…).
If I understand you correctly I believe the following steps might help you. I’m not sure but I believe the script you wrote for checking Facebook like is in Javascript?
1. Hide the form using CSS code.
2. Write Javascript code to call Facebook like checker script.
3.Show the form or point visitor to like your facebok Based on the return value.
I might not completely understand you. But CJT Code Blocks is not conditionally executed.
Please don’t hesitate to ask.
Regards,
AHMeD