I have been supporting an application developed in Classic ASP, SQL Server 2000 in XP environment.
Recently the application got upgraded to SQLServer 2008 R2 with Windows Server 2008 R2 environment.
The problem has started then. In the application screen, a dropdown which was working fine before upgrade is not working now.

Usecase of user action: When user selects an item in dropdown-1, then next moment he/she should be able to click on the dropdown-2 and should be able to select any one of the item from dropdown-2 and then clicks a submit button.

After upgradation (migration), the scenario happening is as below:
User selects an item in dropdown-1 and when clicks on the dropdown-2 , it is not working. He/she is not able to see the items in the dropdown.

Please can I get a prompt help in this regard?