hi there.....
try this, u will exact total hours in hh:mm format
SELECT employeeid,startdate,enddate,RIGHT('0' + CAST(DATEDIFF(HH,StartDate,EndDate) AS VARCHAR),2) + ':' +
RIGHT('0' + CAST(DATEDIFF(MI, StartDate,EndDate) % 60 AS VARCHAR),2) AS 'Total Hours'
FROM tableName
hope this helps...
revert back with ur comments...