U5. Alert Utility Commands
  ViewIt provides support for opening standard Mac alerts and a simpler, string-based form of alert.  Many programmers, however, simply use modal ViewIt windows as alerts, thereby avoiding the use of the ALRT and DITL resources required by standard alerts.

Name  Number  Parameters & Variables used
ShoAlt  153  a,b,c,d,uString,uResult
StpAlt  154  a,b,c,d,uString,uResult
NotAlt  155  a,b,c,d,uString,uResult
CtnAlt  156  a,b,c,d,uString,uResult
  Opens an alert using the Alert, StopAlert, NoteAlert, or CautionAlert toolbox calls.  The parameters a, b, c, and d have the same meaning as those used with MovAlt (described in "Window Utilities").  If uString is not empty, then the first parameter text string is set equal to it (the ^0 item, if any, in the DITL list).  The number of the enabled item pressed by the user to close the alert is returned in uResult.  If the ALRT resource is not found, uResult returns zero.
  If you prefer using SetPrm (described in "String Utilities") or the toolbox call ParamText to set parameter text strings in an alert, be careful to reset uString to an empty string just before calling ShoAlt...CtnAlt, otherwise the contents of uString will be put in the first parameter string.
  WARNING:  ViewIt's positioning of alerts via parameters c and d conflicts with the System 7 "Auto Position" option seen in ResEdit, so do not set this option for ALRT resources that will be positioned by ViewIt.
  FORTRAN NOTE:  To set a string such as uString in FORTRAN to an empty string, set the string equal to a single space.

ShoStr  261  a,b,c,d,uString
StpStr  262  a,b,c,d,uString
NotStr  263  a,b,c,d,uString
CtnStr  264  a,b,c,d,uString
  Creates a temporary window on the main screen in which the message in uString is displayed.  StpStr, NotStr, and CtnStr also display, respectively, the standard Stop, Note, and Caution icons.  Carriage returns and spaces can be used within uString to adjust the appearance of the string.  The next mouse or key press will cause the window to be hidden and disposed of.  If uString is empty, then ViewIt just beeps once without displaying a window.
  The appearance of the string in the window is governed by parameters a, b, c, and d:
  a = font number
  b = size (12 pt. if b = 0)
  c = style (low word) and color (hi word)
    style = sum of following constants:  0 = Plain,
      1 = Bold, 2 = Italic, 4 = Underline, 8 = Outline,
      16 = Shadow, 32 = Condensed, 64 = Extended
    color = one of following constants:
      0 or 33 = black, 30 = white, 205 = red, 341 = green,
      409 = blue, 273 = cyan, 137 = magenta, 69 = yellow
  d = screen position
   -2 = centered above front modal or active modeless
    0 = centered horizontally on main screen
    other = global position (hi word = v, lo word = h)
where c should be calculated as:  c = style + color*65536.