将php值分配给title属性

I'm try to add the return value of my php file to a title attribute. The correct data is return from the php file but for some reason 'appointmentData' is null. I have tried appointmentData.value and .innertext, but none of these work. ideas anyone? The value of appointmentData is "Id = 1 - Name = Blah"I'm try to add the return value of my php file