c#.net

Hi Friends

I want help regarding below problem

"display students name who not paid his/her amount of  installment according to installment format, and format is not fix which would be change in every year",and installment remainder who not paid.
 

 In my software student fee reg form saving values in StudFR table in this form studname,fee,rollno save in textbox,cmbbox name instno:1,2,3

another frm is set installment format on that  fields are cmbbox name instno:1,2,3 cmbbox name instamt:5000,.....,date save in InstFormat named table .this form is to set installment format and this format set remains for one yr , changes according to user need but changes only in a year
so i want to display students name who not paid his/her amount of  installment according to installment format, and format is not fix which would be change in every year",and installment remainder who not paid.

Ex:this is set format for this yr instno is 1,amnt 5000 dte,26jun2012(Last dte of installment) so  those student who not pay this installment amnt

 please send the source code for it or  suggestion

THANKS