The **IfThen** (and **IfThenElse**) functions are used to make conditional execution of expressions.
These function expressions are evaluated the same way as any other type of
expression.

The **IfThen** function has two arguments:

*Condition*- Requires an expression returning a Boolean value. If the result of the Boolean expression is true, the result of the**IfThen**function expression is the*Then*expression. If the result is false, the**IfThen**function expression returns no result.*Then*- The expression that provides the value to the**IfThen**function expression if the condition is true.

The **IfThenElse** function adds a third *Else* argument to the **IfThen**
function. The value of the *Else* argument expression is
returned if the condition argument evaluated to false.