This message is sent by an application to select a string in the list of a combo box. If necessary, the list scrolls the string into view. The text in the edit control of the combo box changes to reflect the new selection and any previous selection in the list is removed.
If the message is successful, the return value is the index of the item selected. If wParam is greater than the number of items in the list or if wParam is -1, the return value is CB_ERR and the selection is cleared.