variable reset

["wap" <wap@sinfo.net>]

Hi,
Is there a way to set a value to a variable before the user selects from a
list? i want the first item on the drop-down list to be set before the
actual selection from the user takes place....
the drop-down list was created like the one in the simple demo, in the
checkout page (country)..
my guess is that if this variable is always initialized, it doesnt matter if
the user goes back a page...
my problem is that when a value for the variable is selected by the user,
and then the user goes back a page, and returns, the old value stays...
any help?
Thanks!