well i have a basic knowledge of c/c++ but no it is not required, as long as your willing to learn, and have a tinyest bit of html & css knowledge you should have no problems whatsoever
You don't have to have any programming knowledge to learn PHP, people with knowledge of other languages will just learn quicker. A good knowledge of HTML is reccomended but not necesary:)
I am good at html & css because I have learned it professionally & can build webpages with them without using any reference. But I wasn't sure if anyone can learn php without programming knowledge because a friend of mine said one needs programming knowledge to proceed to php learning. Thanks for clearing my doubt. Now I have to find resource to learn php.