10/27/11 note: We just added new doc for trace/debug statements, Jack says this topic can now be cut way down. But I didn't do it and I don't want to bug him, so the cutting down has not yet been done.

To manually open the message window (aka "Debug Dialog"), use Ctrl+Shift+Double-Click somewhere on the A-Shell window, preferably not on a control that might respond to a click. This will pop up a "GUI Control Operations" dialog, on which you can click the "Show Debug Dialog" button.

To programmatically open the message window, use one of the TRACE and DEBUG Statements.

The xxxx.OPEN statements are optional and mainly server to allow you to set the title on the message window. The xxxx.PRINT and xxxx.PAUSE statements will automatically open the message window if necessary.

The <msg> and <title> arguments are each limited to a single string expression (which may involve string operations and functions but must rely on concatenation to assemble a compound string of many parts, rather than commas or semicolons as you can do with PRINT). They may also start with zero or more of the following special control variables:

$# (displays the running message count as a message id #)

$T (displays the time in HH:MM:SS format)

$P (displays the program name in brackets, e.g. <MYPROG>)

For example, the following statement

DEBUG.PRINT "$T $P The value of X is: " + X

would appear something like:

11:25:01 <MYPROG> The value of X is: 25