I read from the help on Ajax Description as follows.
returnFunction , if supplied, is a function to be called when the results return, allowing asynchronous execution. If this parameter is not supplied, execution will continue at the next statement after the results return. Do not put MsgBox statements inside your Ajax code: they mess up the event sequence.
I am not using the returnFunction on my Ajax call. The app will run the next statement without waiting for the results return. Is it normal? Or I should put the next statement onto the returnFunction?