function restore-database($dbName, $fileName)
{
[System.Reflection.Assembly]::LoadWithPartialName("Microsoft.SqlServer.Smo") | out-null
[System.IO.Directory]::CreateDirectory($rootFolder) | out-null
$_srv=New-Object "Microsoft.SqlServer.Management.Smo.Server" "(local)" 
$_bck=new-object "Microsoft.SqlServer.Management.Smo.Restore"
$_bck.Action = 'Database' 
$_fil=new-object "Microsoft.SqlServer.Management.Smo.BackupDeviceItem"
$_fil.DeviceType='File'
$_fil.Name=$fileName
$_bck.Devices.Add($_fil)
$_bck.Database=$dbName
$_bck.ReplaceDatabase=true 
$_bck.SqlBackup($_srv)
write-host "Sauvegarde de " $dbName " terminee"
}