IF THEN ELSE

IF expr THEN statement [ELSE statement]

Evaluates the expression ‘expr’ and performs the THEN statement if it is true or skips to the next line if false. The optional ELSE statement is the reverse of the THEN test. This type of IF statement is all on one line.

See also:
ELSE
ELSEIF THEN
ENDIF
IF THEN GOTO
IF THEN ELSE ELSIF ENDIF