How do you check if Record exists

[qmmary]

I have a form that does an insert. I want to see if the record already exists in the database to prevent duplicates. I am a little unsure of when this has to go down. In the codebehind for the controls that is the form or in the Class that I call on to perform the insert. Below is the class that is where I am thinking it goes.\[code\]public class AddContacts{ public int AddContact( string ContactName ) { var myContact = new Solutions.Models.Contact(); myContact.ContactName = ContactName; ItemContext _db = new ItemContext(); _db.Contacts.Add(myContact); _db.SaveChanges(); return myContact.ContactID; }}\[/code\]I have seen it done with If statements that use \[code\].Any()\[/code\] but i cannot get it work right. Nor do I understand what it would need to return in order for me to post a error message \[code\]Contact Name already exists\[/code\].