Mash cream cheese with fork till creamy. Remove any shells from crabmeat (and double-check). Combine cream cheese, onion, lemon juice, salt, and Swiss cheese. Mix well. Add crabmeat. Place mixture in 1 1/2-quarts baking dish and sprinkle grated cheese on top. Bake in oven at 350 degrees till cheese bubbles (approximately 30 minutes).
