The entry field control window procedure responds to this message by setting the zero-based offsets of the bounds of the text that forms the current selection.

If usminsel equals usmaxsel, the current selection becomes an insertion point.

If usminsel equals 0 and usmaxsel is equal to or greater than the text limit set by the EM_SETTEXTLIMIT message, the entire text is selected. Selected text is displayed in reverse color.