Pam, my best wishes to you. It looks like you've received some great advice here.
Omak, you are so wise. I need to meet you in person some day. :-D
My degree is in elem.ed. and I taught in early childhood for 10 years - 4/5 yr olds for 5 years, then newborns-2yr olds for 5 years. I now have two boys of my own ages 4 & 6. When my first was born, my mom took great offense that I was doing things differently than she had, as if I were criticizing her mothering or calling her a failure. No so - I simply had much background experience to pull from to make the choices we thought were best. My MIL was very respectful of our choices because she was willing to listen to our sound reasoning behind them and did her best to support them even at her home. As the boys have grown, we've received only praise from all of our parents. They've been with us in public when strangers comment on how polite and well-mannered our kids are. Our kids aren't perfect of course, but the're learning to be respectful and to be proud of their behavior. Nothing can compare to intrinsic motivation. It pleases us very much that not only are our children well-behaved, but that our parents are proud of us as well.
NOW - we're having to tell the grandparents to not give in all the time! LOL. We have to remind them, "It's okay to say 'No'".
Oh, one other thing: when our children were born, we welcomed them as PART of our family, not RULERS of our family. A thing I think many parents reverse these days. No pedestals in our house simply for being young and cute.