Skip insert in SQL if duplicate exists.

I want to skip or ignore an insert if the values already exist in the table. Below is the SQL I am trying to use but it doesn't seem to work. Can someone assist? I am filling in the values, but they are normally entered by variables in my application and this query is in a loop... that's why I want to ignore if a duplicate exists. Thank you.

INSERT INTO myTable
                  ([ID],[theName],[Auth],[LastModifiedBy])
            VALUES(
                  5
                  ,hello
                  ,yes
                  ,bob
                  )      
            WHERE hello
            NOT IN      (SELECT [ID], [hello]
                         FROM myTable
                         WHERE ID = 5
                         AND AccessID = hello
                  )