@kickycan,
Kicky, why not contact your bank and put a "stop payment" on that cheque, just to make sure, and issue a new one?
Not to scare you, but I have heard that some types are clever enough to be able to erase the ink (on the payee info) and replace it with another name. I think it depends on the type of ink used.
Does your bank offer the type of service where you can pay bills directly from the bank's own ATM? That's probably the safest, convenient way, rather than relying on cheques.