If statements

The if statement is used to conditionally execute a block of sequential statements. The syntax for the if statement is: The condition parts are boolean expressions. If the first condition evaluates to true, then the sequential statement list that follows the THEN will be executed. If the condition evaluates to false, then the next condition (an ELSIF part) is evaluated and the following statement list will be executed if it is true. This continues until a condition evaluates to true or all conditions have been evaluated. If all conditions evaluate to false and there is an ELSE part, then the sequential statement list of the ELSE part is executed. If more than one condition is true then only the statement list of the the first one is executed.