hi i Think This Code helps you
SELECT * FROM TABLE
WHERE DATE BETWEEN
Convert(varchar,CreatedOn,103)=CONVERT(varchar,ISNULL('01/02/2012',CreatedOn),103)
AND Convert(varchar,CreatedOn,103)=CONVERT(varchar,ISNULL('05/05/2012',CreatedOn),103)
"103" stands BRITISH/FRENCH FORMAT
for more search this link
http://www.sql-server-helper.com/tips/date-formats.aspx[
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