How do you lookup an ID to get a name to place in a textbox?

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Hi,

I have a value that represents a FunctionID that gets sent (in the
querystring) to a page. When loading this page I need to display the
corresponding FunctionName for that FunctionID in a textbox (not inside any
other control) to show what Function the page is referring to. Very easy
with a combobox but can't see how to do it for a textbox.

I would like to have a SQLDataSource that caches the ID, Name lookup query
(as it doesn't change very often) so that I can just use a filter expression
each time rather than going to the database every single time the page is
loaded. However I can't even see how to get the result into the textbox.

txtFuncPMCID.Text = Request.QueryString("FuncPMCID")

will get the ID in during the load event, but how do I get the name into it?

Thanks,

Rob