Iframes - calling from a different parent and populating from url

[dickiebow]

I have a page which I will call A with links that call another parent page B that in turn has at least two iframes (may add more later) one of which, C,  has the MYSQl calls to provide the detail. The iframe will happily respond to GET calls from itself so its internal code is OK but when I try to pass a variable through the parent B it complains of MYSQL statement errors. I even coded the parent B to take the GET from A and pass it as a new variable to C (it opens the right page as a result of A ) but had the same problem.

 

No amount of Googling has produced an explanation - most answers seem to be between iframes under the same parent.