can i know wheather its a windows application r the webbased application
in the web-based application if u r going to use the database as source to display the data in the dropdown
we give it as
DropDownList3.DataSource = Class2.details().Tables[0];
DropDownList3.DataBind();
here class2 is the class having the functionname caleed details in that we r going to have the sql query to display the data fro the datbase to the dropdown(select query).
then we will assing that dropdownlistsdata into the session
as
session["anyname"]=dropdownlist3.selecteditem.text;
then according to u we can give the timeout values in the web.config file also