SELECT CASE is a construction for evaluating and acting on sets of conditions.

SELECT CASE var  - defines the beginning of the construct.  It is followed by the name variable that will be evaluated.  The variable can be a numeric variable or a string variable, or an expression such as "a+b".

CASE value - following the SELECT CASE statement, are individual CASE statements, specifying the conditions to evaluate for the selected variable. Code after the "case" statement is executed if that particular case evaluates to TRUE.  There is no limit to the number of conditions that can be used for evaluation.

CASE ELSE - defines a block of code to be executed if the selected value does not fulfil any other CASE statements.

END SELECT - signals the end of the SELECT CASE construct.

