SQL Server Backup Stored Procedure and Usage and also the Batch file

Batch File:

forfiles /P 
readynas\DevelopersBackup\SEARCHSERVER /M RoadKill*.* /D -20 /C "cmd /c del @path"

sqlcmd -U sa -P Password -S Searchserver -Q "EXEC sp_BackupDatabase @backuplocation='
readynas\DevelopersBackup\SEARCHSERVER\', @databaseName='RoadKill', @backupType='F'"

Stored Procedure:

USE [master]

GO

SET ANSI_NULLS ON

GO

SET QUOTED_IDENTIFIER ON

GO

CREATE PROCEDURE [dbo].[sp_BackupDatabase] @databaseName sysname, @backupType CHAR(1), @backuplocation varchar(500)

AS

BEGIN

SET NOCOUNT ON;

DECLARE @sqlCommand NVARCHAR(1000)

DECLARE @dateTime NVARCHAR(20)

SELECT @dateTime = REPLACE(CONVERT(VARCHAR, GETDATE(),111),'/','') + REPLACE(CONVERT(VARCHAR, GETDATE(),108),':','')

IF @backupType = 'F'

SET @sqlCommand = 'BACKUP DATABASE ' + @databaseName + ' TO DISK = ''' + @backuplocation + @databaseName + '_Full_' + @dateTime + '.BAK'''

IF @backupType = 'D'

SET @sqlCommand = 'BACKUP DATABASE ' + @databaseName + ' TO DISK = ''' + @backuplocation + @databaseName + '_Diff_' + @dateTime + '.BAK'' WITH DIFFERENTIAL'

IF @backupType = 'L'

SET @sqlCommand = 'BACKUP LOG ' + @databaseName + ' TO DISK = ''' + @backuplocation + @databaseName + '_Log_' + @dateTime + '.TRN''' EXECUTE sp_executesql @sqlCommand

END