Adds a string to the list box of a combo box.
If the list box was not created with the CBS_SORT style, the string is added to the end of the list. Otherwise, the string is inserted into the list, and the list is sorted.
This function is not supported by the Windows ComboBoxEx control. For more information on this control, see ComboBoxEx Controls in the Windows SDK.
To insert a string into a specific location within the list, use the InsertString member function.