I have a simple php program which is getting the data from the url, but I want to check whether it contains a alphabet or not. 

The data which I get from the url is as follows `?query=seller,12`. I used `ctype_alpha()` for this, but I am getting no result for this. I have a rough idea that it can be done by `preg_match()` but I don't how to do it. 

Please help me as I am beginner to php. 

Thanks in advance