Search Filtering Using Two dropdownlists and show the filtered data in data list

I am building an auto buy and sell website for my semester project using 3 tier architecture. i want to include a filter search in my site i.e there will be two dropdownlists from which users wil select and a search button.. the two dropdownlists will be City(select city) and make(select brand e.g honda).
When users select from these dropdownlists and click search, it will fetch the related data from the database and show them in datalist. the data includes maker,model,city,Image and description.