As everyone has said, "Clark" could very well change his name. From eHow:
If you're a man changing your name at marriage, check your marriage certificate to see if there is a space to indicate a name change. If not, you will need court papers to legally change your name. Contact a local attorney to find out the procedure for name changing in your state. (This is not necessary for women.)
Whatever they change to has to be done on the marriage certificate. They balked when I went to change my name because I'd signed my maiden name on the certificate. But I had figured I wasn't married yet, so why should I sign a name that's not yet mine?? All they did was tell me I did wrong, and then changed it anyway.
