<p>how do i make an autocomplete textbox in asp?
but i need to get the autocomplete data by querying the database. 
I dont really know how to explain this, sory if theres not enough detail. 
i cant use ajax, because i think i will have compability issues with my old app.
so im thinking of doing this using java script. or is there a way to do this by using .net?
im using C# for codebehind. thanks</p>

It's going to be a lot of effort without using some third party autocomplete I think - not sure what you mean by 'I can't use ajax', but how about using the
ASP.NET AJAX autocomplete control
, setting the
```
ServiceMethod
```
property to a static Page Method in your code behind? That keeps it contained within your page at least.
The Page Method can go off to your database, and return a String[] of results.
If you decide to use it, you'll need to set the
```
EnablePageMethods
```
property to
```
true
```
in the
```
<asp:ScriptManager>
```
control.