The sorting is not working

Hi all, i have the following code

SELECT CASE WHEN [Service Header].[Document Type] = 0 THEN 'Quote' ELSE 'ORDER' END AS [Doc Type], [Service Header].[Responsibility Center],
[Service Header].No_,
CASE WHEN [Service Header].Status = 0 THEN 'Pending' WHEN [Service Header].Status = 1 THEN 'In Process' WHEN [Service Header].Status = 2 THEN
'Finished' WHEN [Service Header].Status = 3 THEN 'On Hold' ELSE 'Waiting Parts' END AS [Contract Status], CONVERT(VARCHAR(12),
[Service Header].[Order Date], 103) AS OrderDate, [Service Header].Name, [Service Header].Description, [Service Header].[Resource Code],
[Service Header].[Customer No_], [Service Header].[Contract No_],
CASE WHEN [Service Header].[Response Date] <= '01/01/1900' THEN '' ELSE CONVERT(VARCHAR(12), [Service Header].[Response Date], 103)
END AS ResponseDate, Resource.Name AS [Resource Name], CASE WHEN ([Service Header].[Job Type] = 0)
THEN 'BILLABLE' WHEN [Service Header].[Job Type] = 1 THEN 'CONTRACT' ELSE 'WARRANTY' END AS JobType
FROM dbo.[CompanyName$Service Header] AS [Service Header] LEFT OUTER JOIN
dbo.[CompanyName$Resource] AS Resource ON [Service Header].[Resource Code] = Resource.No_
WHERE ([Service Header].No_ LIKE 'FS%')
ORDER BY Resource.Name, CONVERT(VARCHAR(12), [Service Header].[Order Date], 103) DESC

The sorting for resource name is working fine but it is not working for order Date. year 2009 is coming before 2010 for the same resource name.
Am i missing something in this.

Sorry for this post. I think without doing research on my code i just put in the forum.

Yes. So i just displayed in VArchar but sorted using Datetime.

Just look at your ORDER BY clause -
ORDER BY Resource.Name, CONVERT(VARCHAR(12), [Service Header].[Order Date], 103) DESC
You are most definitely sorting by the string returned by the CONVERT function.
To order by a datetime column, just refer to the column - no bells, no whistles ...
ORDER BY Resource.Name, [Service Header].[Order Date] DESC