Online helps list the syntax of each command including the parameters, keywords, and remarks. To access the online help, type HELP in the McIDAS text and command window followed by the command for which you'd like more information. You can find additional command information in the Unidata McIDAS-X User's Guide.

1. Find the help for the ZLM command.

   Type: HELP ZLM

   The help text appears in the active text frame as shown below:

   ZLM -- Draws graphics using the mouse
      ZLM BOX color height width < keywords >
      ZLM CIRCLE color height width < keywords >
      ZLM DRAW color SMOOTH= 
      ZLM FILL color height width < keywords >
      ZLM FREE color
   Parameters:
      BOX    | draws a box
      CIRCLE | draws a circle or ellipse
      DRAW   | draws a smooth, continuous line as you move the mouse 
      FILL   | draws and fills a box
      FREE   | draws straight lines between points selected with mouse (def)
      color  | graphics color level, use 0 to erase with FILL option (def=3)
      height | height of the box, circle or ellipse, in pixels
               (def=cursor height)
      width  | width of the box, circle or ellipse, in pixels
               (def=cursor width)
   Keywords:
      GRA= | graphics frame number to display output; valid only with MODE=N
             and BOX, CIRCLE, or FILL option (def=current)
      MODe=I | interactive mode (def)
          =N | non-interactive "batch" mode; draws shape centered at line
               and element position specified in POS keyword on the graphics
               frame specified with the GRA keyword; valid only with BOX,
               CIRCLE, or FILL option
      POS=line ele | TV line and element position to center the shape on;
                     valid only with MODE=N and BOX, CIRCLE, or FILL option
                     (def=current cursor position)
      SMOoth= | number of samples to take for the running average with the
                DRAW option; the range is 1-50; larger numbers produce
                smoother lines (def=3)
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2. Get a listing of all the commands and a brief description of their functions.

   Type: HELP

3. If you are entering a command and have forgotten the syntax, you can get a brief listing of the syntax by pressing Alt ?. Show the syntax of the IMGDISP command.

   Type: IMGDISP (but don't press Enter)

   Press: Alt ?

   The syntax of the IMGDISP command is listed in the current text frame.

4. Use the Esc key to clear the line.

   Press: Esc