ssrs parameter values that user can select

In an new SSRS 2008 the endyear parameter has,

1. the following is the default values sql: 
Select
case
    when MONTH (GETDATE()) BETWEEN 07 and 12
            then  Year(GETDATE()) +  1
    else
            year(GETDATE())
END as  Default_Year

2. The following is the available values sql:

SELECT distinct endYear as ActiveSchoolYear
  FROM   vCalendar
  where activeSchoolYear = 1

The endyear parameter DOES NOT have any of the following options selected:
allow blank value, allow null value, or allow multiple value.

When the report is running the value from the 'available values sql' looks like it is being used.
In the 'endYear' parameter, The message '<Select a value>' is displayed and the user has to select the year value that is available.

Thus I have the following questions:

1. How come the query from the 'default values' is not accessible? How can I make the sql from the 'default sql' be available?
2. How come the message '<Select a value>' is displayed and the user has to select the year value that is available? How can I make it so the user does not need to select a value from the drop down list? I just want the value to be selected automatically.