dynamic columns in rad grid

[arun]

i am having 3 rad comboboxes on a page and on the selected index change event ofone of them a rad grid must appear. In that grid one column is coded in aspx page but other columns should appear as which month has been selected in the above rad combobox. so if january is selected 31 column must appear and accordingly. now in each those cells of column rad comboboxes should come and to be binded to the datatable containing some data as selection from remaining rad comboboxes.

any help will be grateful
thanks in advance
arun