JScript  

'default' can only appear once in a 'switch' statement

You attempted to use the default statement more than once within a switch statement. The default case is always the last case statement in a switch statement (it is the fall-through case).

To correct this error

Remove any extra default case statements from your switch statement (use at most one default case statement in your switch statement).

See Also

Switch | Controlling Program Flow | JScript Reserved Keywords