I have a asp.net 3.5, C# web app. Need help with filtering mechanism. Backend C# class file takes in a dataset thru session variable and searches it by linq query, returns results in a datatable. This datable is then linked to listbox item to display search results. I already have a working query that searches and returns results for each of teh 5 DDLs. But this query has to add filters dynamically because there are 5 dropdownlists and user can select from one or all or any. To add/search these selections dynamically to linq query I need Linq query expression. Want a quick help with this task. Anyone can help, this is for few hours task.