168. Drawing text boxes (for Master/Compact)
     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
This Procedure makes use of the extra characters built-in to the Master. It
enables you to draw a neat box round text, without resorting to graphics
commands such as MOVE and DRAW. You specify the Left, Bottom, Right and Top
TAB X-Y co-ordinates of the box, just as if defining a text window. The VDU28
command in line 1040 defines a text window inside the box, and can be omitted
if not required. The example shown is in Mode 0, but it works in any 32-line
Mode, ie 0/1/2/4/5, but will not look very nice in Modes 3 & 6 unless you
make use of the "STRIPEY BACKGROUND" hint given in the 1986 tips compilation.

  10 MODE0:PROCbox(20,20,60,10):END
  20 :
1000 DEFPROCbox(L%,B%,R%,T%):LOCALV%
1010 PRINTTAB(L%,T%)CHR$(163)STRING$(R%-L%-1,CHR$(166))CHR$(165)
1020 FORV%=T%+1TOB%-1:VDU31,L%,V%,169,31,R%,V%,169:NEXT
1030 PRINTTAB(L%,B%)CHR$(170)STRING$(R%-L%-1,CHR$(166))CHR$(172);
1040 VDU28,L%+1,B%-1,R%-1,T%+1:REM Omit if not required
1050 ENDPROC