Puppy screaming in crate when left alone NEED HELP.?

this is what i did, i had a puppy who would scream like someone is murdering her. I put my pup in the crate and walked away out of sight, make sure she isn't watching you. Walk out and a couple seconds walk back in. The dog needs to know you will be back for her. Some dogs think you are abandoning them so if you keep up walking in and out of the room the dog will soon realizes any second now you will be back. Ignoring the dog is key. Keep this up, if it sounds dumb or tiring, boring perhaps. trust me it worked for my dog. Its like peek a boo with your dog, and when the dog is quiet is time for giving him a treat and phrase. every time leave for a little bit more seconds until you get into minutes. gradually work up to 30 Min's then to 40 Min's you the idea.