First use an existing script in /etc/init.d as a modle. You should have only
one dhcp script and it should contain start:|stop statements, then use
chkconfig to manage init processes here the RH man page:"
A couple of always when writing scripts:
1. Always start scripts with a "shebang" #!/bin/sh or #!/bin/bash
2. Aways use compete path to commands
You could also just put it in rc.local?