Problem passing data between modal dialog and parent window

Hi!

I'm really having trouble sending data from a modal dialog window to a parent window in asp.net

I have a parent page with several textboxes and each textbox has a button that opens a lookup child window
(modal dialog) when clicked. The lookup pages have filtered datagrid data, that when are selected should be passed back to the parent page.

My problems are:

1- my modal dialog has a couple of dependent dropdownlists to filter the datagrid information. Everytime I select an option from the first dropdownlist, the page is reloaded and it opens in a new window normal window. And I still have the modal dialog open. I want to use the modal dialog, not the new opened window.

2 - I have already been able to send data from the dialog to the parent page with querystrings, but I would prefer not to use this method, besides, like I've described above, I have to open several lookup pages, and each time I open another one, I loose the data passed from the previous, because the window location (URL) becomes diferent due to the new querystring and the page loads again and all the controls loose their info.


Please help me... send a post

Best regards
Mario Ramos