I know your main question is about eating, but I have a question first: Is his weight OK? Is he gaining like he should be? Does he have enough dirty diapers? If so, then at least you know he's getting calories in. If not, I'd start with a visit to the pediatrician to make sure nothing is physically wrong. Assuming nothing is wrong, consider the following:
Cut down on his milk comsumption. If he likes it, he'll drink it and it will fill him up so much that he won't want to eat. I'd try to make sure that he doesn't have any milk before mealtimes so that he's hungry. My daughter was so picky when she was about 15 months and although I kept trying to get her to eat certain foods, she would refuse. I just never gave up, meaning I offered her the same thing more than a dozen times and eventually, she'd eat it. Now, at 4, she'll try lots of new things eats many of the foods that as a baby she refused over and over.
Try to hide foods within other foods, too. Meatballs are a really easy food to make where you can add lots of shredded veggies to the recipe (zuchini and carrots are easy to hide in there). That way, one meatball is actually a meal.
If you child refuses to eat fruit but drinks juice, try this: Add water to a jar of baby food so that it's liquidy enough to drink from a sippy cup. Your baby will get the entire jar of food and will hopefully develop a taste for fruit along the way.
Most of all, keep trying over and over and don't give in too easily!
Good luck!
M.