Add a client-side check: if user does not enter any search values, prompt the user with a dialog box to confirm that the user wishes to go ahead with a search for all documents. This is equivalent to the behavior in the simple search box.
Added a hidden input field for siteValue with a value of "ALLSITES". This is a substitute for the siteValue drop-down list that is used at LTER whose default value is also "ALLSITES". Either the hidden input field or the drop-down list should be commented-out, but not both. (This is documented in the internal comments.)