Bracket for IF statement in Stored Procedure

try begin and end instead

IF(@item!=0)
begin
/*Do stub*/
RETURN   
/* without the brakets , this return does not belong to if  */
end 

Instead of RETURN, you can also use ELSE:

if @item != 0
begin
   -- Do stub
end
else
begin
    -- Do some stubs  
    -- and if the condition of the IF is false, this statement can't be reached
end

Plus:

• you don't need the brackets around the IF clause
• you have to use -- instead of // for comments (see my example)