[sql] how to call scalar function in sql server 2008

I have created a Scalar Functions, it was created successfully, but when I call the function using select statement, it says Invalid object name 'dbo.fun_functional_score'.

my function:

 ALTER function [dbo].[fun_functional_score] (@phy_id varchar(20))
 returns  varchar(50)

as
begin 

declare @level_initial int, @level_current int

-- initial functional score
set @level_initial=(SELECT pflag.fun_level
FROM tbl_phy_demographic_details as [phy] 
    inner join tbl_all_purple_flag_level as [pflag] on phy.Demographic_id=pflag.Id 
WHERE phy.Physicion_id=@phy_id
    and pflag.visited_count=(select MAX(visited_count)-1 from tbl_all_purple_flag_level ))


-- current functional score
set @level_current=(SELECT pflag.fun_level
FROM tbl_phy_demographic_details as [phy] 
    inner join tbl_all_purple_flag_level as [pflag] on phy.Demographic_id=pflag.Id 
WHERE phy.Physicion_id=@phy_id
    and pflag.visited_count=(select MAX(visited_count) from tbl_all_purple_flag_level ))


--to calculate functional score
declare @fun_level varchar(20),@result varchar(50)

set  @fun_level=@level_current-@level_initial;

 if @fun_level = 0   set @result='Maintained' 
if @fun_level = '-1'  set @result='Minor Improvement' 
if @fun_level = '-2'  set @result='Moderate Improvement' 
if @fun_level = '-3'  set @result='Significant Improvement' 
if @fun_level =  '-4'  set @result='Substantial Improvement' 
if @fun_level =  '1'  set @result='Minor Reduction' 
if @fun_level =  '2'  set @result='Moderate Reduction' 
if @fun_level =  '3'  set @result='Significant Reduction' 
if @fun_level =  '4'  set @result='Substantial Reduction' 




return @result

end

i used this select to call

 select * from dbo.fun_functional_score('01091400003') as [er]

or

 select * from dbo.fun_functional_score('01091400003') 

both showing error "Invalid object name 'dbo.fun_functional_score'. "

where i made error . can anyone help me...

You have a scalar valued function as opposed to a table valued function. The from clause is used for tables. Just query the value directly in the column list.

select dbo.fun_functional_score('01091400003')

For some reason I was not able to use my scalar function until I referenced it using brackets, like so:

select [dbo].[fun_functional_score]('01091400003')

For Scalar Function Syntax is

Select dbo.Function_Name(parameter_name)

Select dbo.Department_Employee_Count('HR')