PROCEDURE DELETE((* source   *) VAR argument : DSTRING;
		 (* starting *) posn,
		 (* # chars  *) span  : integer );
{ last modified: 7/11/81 }
{++++++++++++++++++++++++++++++++++++++++++++++++}
{+  Returns:					+}
{+	argument with span characters deleted	+}
{+  Errors:					+}
{+	returns argument string intact		+}
{++++++++++++++++++++++++++++++++++++++++++++++++}
label 1;{ error exit }
var	len: integer;
	overage: integer;
begin
  len := length(argument);
  { check for valid parameters first }
  if ( posn<1 ) or ( posn>len )
     or ( span<1 ) then {QUIT} goto 1;
  { is the entire string being deleted? }
  if ( posn=1 ) and ( span>=len ) then begin
     setlength(argument,0); { argument := ''; }
     {terminate} goto 1
  end;
  { check for excess span }
  if (posn+span-1)>len then begin { overage }
      overage := (posn+span-1) - len;
      span := span - overage
  end;
  { Move chars as long as Movefrom <= len }
  { Movefrom := (posn + span); }
  Repeat
     argument[posn] := argument[posn+span];
     posn := posn + 1;
  Until ( (posn+span)>len );
  posn := posn - 1;{ qualify posn }
  setlength( argument, posn );
1:{terminate};
end{ of DELETE };
 ( (posn+span)>len );
  posn := posn - 1;{ qualify posn }
  setlength( ar