Doing a Multiple Search

I know this must be an easy solution, just not seeing what it is. I have tried to add several options to the below code but can't seem to get it right. Here is the Base Line I am working with: $Query="SELECT * from $TableName WHERE lastname='$Array[lastname] AND firstname='$Array[firstname]' "; What I ant to be able to do is a search on both the lastname and the firstname so if someone just puts in the last name it will display all people with the queried last name regardless of the first name. So for the visual representation If I search for Bob Smith, it will give me: Smith Bob If I search by last name Smith, it will give me Smith Bob Smith John Smith Mike Any and all help would be greatly appreciated. Thanks in Advance Jess