Populating a DropDownList

I am populating a dropdowm list from a SortedList and want to order the data in the dropdownlist by the displayed data and not the value. How can I do this ?put the data into an arraylist and then bind the arraylist to the DropDownList - - you can sort the arraylist anyway you'd like.
How do I put the data in an array list and then sort it. Do you have an example.
How do you have a database valueand a display value in the array list ?
please i'm making a site in a page of this site i had two dropdownlist ,the first is for the comapny and the other is for the models products of one company...
how can i make the ddl of the company to be when i select one of them, the another ddl changes its contenent to be just the models of this company or this selection..

if any body know please post the codes and the html apperance codes