Hi ravi338,
Since the fields are changing and not fixed it is clear that something dynamic has to be used.
So all I can tell you is this exercise can be worked upon by identifying which "changing" property can be made use of.
Observe certain things, do some analysis and identify which property (or properties) are changing for a particular field (eg, label, textbox) and then see if that can be used to identify an element and then write data to it. There could be more than one ways to work on this activity. So do not stick with one approach.