title: linq-to-sql user concurrency
body: <p>I am currently working on a C# windows form with linq-to-sql that selects a row from a SQL table and then allows the user to edit the fields in that row.  This form will be used by multiple users at a time and I would like to have it so when someone has selected a row and is currently entering data in the form (with which the row will be updated once the user hits a button on the form) no one else may select that row.  Once the user hits the button to execute an update query the updated row should be selectable again.  Essentially the process is:</p>
  
  <p>user selects row-->row becomes unselectable by other users-->user modifies row fields values-->user submits and row updates-->row becomes selectable again.</p>
  
  <p>Is there some sort of existing functionality I can use to accomplish this or will I need to create a table that tracks which rows are unselectable and have the application query that table before selecting rows (ie query table to see if row is unavailable, if not insert rowid user is editing, then delete row after user has submitted changes)?</p>