What do you mean by editting? As in, someone in an application is viewing the record? You'll need to implement your own "locked" system. For example, add a column (maybe called [Editting]) of the datatype bit, and set them all the 0 (probably with a default of 0). Then, when someone clicks the "edit" button in the application is tries to update the value to 1, provided the value isn't already. if it manages to change it, then the user can edit the record, and when the save/cancel the value is set back to 0.

I realise this is a vague answer, however. the question is as well, with little detail on the environment, data, software, scope, etc etc. For a much more specific answer, you'll need to write a far for specific question.