Form Application: How to refresh a SELECT field when focus leaves a TEXT field ?

[TABLE=“border: 0, cellpadding: 4, cellspacing: 1, height: 18”]
[TR]
[TD=“align: left”]Hello,

		I have a form application with two fields: field A is of type Text and field B is of type Select.
		
		I want to refresh B (reload the select list from database) when focus leaves from A.
		
		Something like: OnBlur A ----> refresh B
		
		Can you help with some example ?
		
		Please note that I know how to do it if A is of type Select (I just use Ajax to concatenete a click on A to refresh B) but I don't know how to do it when A is of type Text.
		
		Thanks, Max
		 [/TD]
	[/TR]
 [/TABLE]