Script to check db size available space

USE TempDB
       SELECT
              a.FILEID,
              CONVERT(decimal(12,2),ROUND(a.size/128.000,2)) as [FILESIZEINMB] ,
              CONVERT(decimal(12,2),ROUND(fileproperty(a.name,'SpaceUsed')/128.000,2)) as [SPACEUSEDINMB],
              CONVERT(decimal(12,2),ROUND((a.size-fileproperty(a.name,'SpaceUsed'))/128.000,2)) as [FREESPACEINMB],
              a.name as [DATABASENAME],
              a.FILENAME as [FILENAME]

       FROM      dbo.sysfiles a