IsReadingText indicates if the API is currently reading text from the user. Calling StartReadingText will set this to true, and it becomes false when the user presses enter or escape. At this point you can read the string entered as ASCII.
Where is it: SGSDK_INPUT
function IsReadingText(): Boolean;
public bool Input.IsReadingText();
Visual Basic .NET
Public Function Input.IsReadingText() As Boolean
Visual Basic 6
Public Function MouseAndKey.IsReadingText() As Boolean