'Do...Loop Statements
'   execute a program block repeately while a Boolean Condiltion is true or else it exits the loop.
'   The general form is
'       DO[{WHILE|UNTIL} condition]
'       [statements]
'       [Exit Do]
'       [statements]
'       LOOP[{WHILE|UNTIL} condtion]
'   There are four ways of writing this loop. Two ways use WHILE, the other two ways use UNTIL.
'   WHILE counts from bottom to top and UNTIL counts from top to bottom.


Sub Main()

    Dim x As Short
    x=1
    Do While x<5
        Debug "*"
        x+=1        'display 4 asterisks
    Loop
   
    Debug CR        'moves to next line
    x=1
    Do
        Debug "*"
        x+=1        'display 4 asterisks
    Loop While x<5
   
    Debug CR
    x = 5
    Do Until x=0
        Debug "*"
        x-=1        'display 5 asterisks
    Loop
   
    Debug CR
    x = 5  
    Do
        Debug "*"
        x-=1        'display 5 asterisks
    Loop Until x=0
End Sub