#### IsNull

##### IsNull(DBfield a)

This function tells whether a specified value (especially the value of a DBField) is null or not. If the value is Null, the function will return True, otherwise False.

Parameter

a - A specified value especially a value of a DBField.

Return value

The return value is True or False.

Examples

- The return value of the following statement is false.

  `IsNull(2.5)`

- If you build a report about customer order, suppose one of the values of the field "Shipped" is Null, the return value of the following statement is true.

  `IsNull(@shipped)`