IF condition1 THEN
{...statements to execute when condition1 is TRUE...}
ELSIF condition2 THEN
{...statements to execute when condition1 is FALSE and condition2 is TRUE...}
END IF;
IF condition1 THEN
{...statements to execute when condition1 is TRUE...}
ELSIF condition2 THEN
{...statements to execute when condition1 is FALSE and condition2 is TRUE...}
END IF;