asp.net - objectdatasource: controlling multi-select listbox controlparameter

i have form contains gridview control databound an objectdatasource control. there several textbox controls already being used controlparameters objectdatasource. i also have tradition information vigilant objectdatasource compared {typename="mydataclass"}. values upheld objectdatasource mydataclass.

now i need also multi-select listbox controlparameter. i selectedvalue parameter listbox, objectdatasource wholly observant initial comparison vigilant list.

here's question: i multi-select listbox values upheld tradition vigilant "mydataclass" instead only initial selected? hence ["multi-select"]

thanks any help!