Most accurate way is to go to Browse foods, instead of Search. Find poultry, then chicken, then breast, then how prepared, then with or without skin. I do chicken breast this way and it comes up to about 45 calories an ounce, cooked, which is probably similar to your 4 oz uncooked (I assume) at about 140 calories (weight is lost during cooking). Alternatively, you could always enter the info from the package as a custom food.
"If you drop an egg, you don't say, 'Oh, shoot' and drop the other 11, do you?"
-Source unknown, but obviously brilliant
Reached goal 4/16/2010...but kind of afraid to look these days