init comboBox from DataBase

hi,

i have 2 combo boxes and when the user choose some value from combo1 i need to get to dataBase and then fill combo2 with values.

i thouth about using a dataset to save the possible values of combo2 so i wont need to get to the dataBase every time.

how can i fill combo2 every time the user change the value in combo1?

i need to do it in javaScript , but how can i get to the dataSet from JavaScript?

or maybe there is another way?

thanks in advanced

I don't know how to get data from DB using javascript. But you can try this: http://www.ajaxpro.info/default.aspx.

If you want use code-behind, I suggest you to store data in Cache (HttpContext.Current.Cache) before loading.