List<> and Contains scenario, compare get excluded and included using asp.net 2.0

I have two List's that contain a object of Tag like List<Tag> i need to find excluded and included to do an update operation how do find the difference in them both since they contain a Tag object. Can you use Contains function with a Tag object inside the list need some help. 
Im using asp.net 2.0 so please if you can help me do it in that language please.

List<Tag> tag1 = new List<Tag>() tag1.Add(new Tag("Apples")); tag1.Add(new Tag("Oranges")); tag1.Add(new Tag("Pears")); List<Tag> tag2 = new List<Tag>() tag2.Add(new Tag("Apples")); tag2.Add(new Tag("Bananas")); txtExcluded.Text = list1; txtIncluded.Text = list2









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