DO and END – Block and Loop commands

Use the DO and END commands to designate a block of code to run together. You can either use them to group multiple commands for IF-THEN-ELSE or to repeat blocks of code.

The following list shows the variants of the DO commands:
Block
A single run block of code: DO
Repeat
A simple repeating block: DO x
Iterative
A block that increments or decrements a variable: DO v = x TO y BY z
While
A block that runs only while a condition is true: DO WHILE expression
Until
A block that runs until a condition is true: DO UNTIL expression
Forever
A block that runs until LEAVE or EXIT is run.