Jan 11, 2010 11:12 AM|Das.Sandeep|LINK
If your combo ID is Country. so you can pass text or string in place of "USA" in below syntax and set it's index. Hope it will solve your problem, may no me if you require more info.
Mark as answer if it helps.
int nCountryIndex = Country.Items.IndexOf(Country.Items.FindByValue("USA"));
if (nCountryIndex > -1)
Country.Items[nCountryIndex ].Selected = true;