let me explain in a better way
1st parameter "Date options" with static values Last full month,Custom date
2nd parameter "start date"
When I select Last full month value the 2nd parameter "start date" should be disable and shldnt showup,it should only show up when I select Custom date value in the "date options" parameter.
Disabling start parameter mean that should not be there when Last full month value was selected.
does this make sense ?