How to get the in between date from the months using c#.net

hi,

i have problem to get the inbetween dates between the months,

for example,

table design:

employee fromdate Todate
kavi 05-1-2012 07-1-2012 (mm-dd-yyyy)

means

Actually the employee kavi apply the leave between those above days.that particular leaves are approved.

if employee kavi again apply the leave between these dates 05-1-2012 to 07-1-2012
they didt allow to apply the leave,because their is already the leave record for particular months


example
i kavi apply the leave between these dates 05-10-2012 to 06-06-2012 means
they didt allow,

i need to check the dates for particular employee is applied or not between before applied dates in database

some one help to get the dates between the months

Thanks in advance..

Regards
Kavi.n