i get the error in following code

Function ReadFile(ByVal sPath As String) As Byte

    Dim data As Byte
    data = Nothing

    Dim fInfo As FileInfo
    fInfo = New FileInfo(sPath)

    Dim numBytes As Long
    numBytes = fInfo.Length

    Dim fStream As FileStream
    fStream = New FileStream(sPath, FileMode.Open, FileAccess.Read)

    Dim br As BinaryReader
    br = New BinaryReader(fStream)

    data = Convert.ToByte(br.ReadBytes(numBytes)) `getting error on this line`
    Return data
End Function