[16th day] Chg: SELECT / INSERT button's Show/Hide button
[16th day] Chg: Change to image the delete button.
[16th day] Chg: Can able to undo of the Delete.
[17th day] Chg: Changed to ajax also the first select.
[17th day] Chg: Reject an invalid value.(checked the type of the column)
[17th day] Chg: Easy to understand the login elapsed time.