How to use ASP .NET dropdown with ajax

Greeting,

I'm beginer of ajax technology and now i need to create two dropdown in MVC project for example:

First dropdown has the list of classroom [601,602,603] when i choose one then next dropdown will has the list of student belong to e开发者_StackOverflow中文版ach class room.

Now, I already create the repository class that has method GetStudentByClassroomName() and already connect to the database.

Can anyone give me a suggestion how to create it or any technology to create the dropdown like this?

Thank you very much ^_^

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Look here - similar problem (cascading drop down)

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check the CascadingDropDown from the ajaxcontroltoolkit.

http://www.asp.net/ajax/ajaxcontroltoolkit/Samples/CascadingDropDown/CascadingDropDown.aspx