ASP.NET MVC Logical Question

Question

Can anyone please provide me with the logic for:

 

1. I have a drop down list and I got its value from the data base i.e SQL server and I binded it     to the drop down using ASP .net MVC

 

2. If the drop down value is value it is displaying 1 record(getting one record from database         and showing) and same in case of drop down values for value=2, 2 records from database     on so on...... 

 

3. For suppose the dropdown value is 2 and it is showing 2 records, then the end user want       to add the records and he chose 6 as drop down value then 4records has to come                 i.e(2+4=6)   and later if he chose 4 as drop down value then 2 records must be removed          i.e(6-2=4)  

 

Note:  The 2 records that are obtained from the data base must not be removed , only adding            extra records and removing them and then send them to the data base along with the              2 records