or
function ResetCombo(combo) { if (combo) { combo.clearItems(); combo.set_text(""); } }function LocationSelectedIndexChanged<%= ID %>(sender, eventArgs) { var locationCombo = $find("<%= rcbLocation.ClientID %>"); var addressCombo = $find("<%= rcbAddress.ClientID %>"); var contactCombo = $find("<%= rcbContact.ClientID %>"); var contact2Combo = $find("<%= rcbContact2.ClientID %>"); var value = locationCombo.get_value(); ResetCombo(addressCombo); // Items clear on on first index change ResetCombo(contactCombo); ResetCombo(contact2Combo); if (contactCombo) contactCombo.disable(); if (contact2Combo) contact2Combo.disable(); if (value == "") { if (addressCombo) addressCombo.disable(); } else { if (addressCombo) { addressCombo.enable(); addressCombo.requestItems("", false); // Fires only on first time index is changed } } }