Determining if a control event will fire outside its event handler

Hi all
I have a web form with (among other controls) a DropDownList and a Button. The DropDownList does not AutoPostBack, but the Button does trigger a PostBack.
The code that the Button's event handler runs really needs to know if the value of the DropDownList has changed. Is there a way that it can determine whether the DropDownList's SelectedIndexChanged event has/will/would fire?
The only other way I can think of to do this is store the original value of the DropDownList in ViewState before sending the page to the client, then comparing this value with the value of the DropDownList when the page is posted back, but that seems really clumsy.
Thanks
David

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