Example: The Query

define function findMatches()
{
for $i in $metadata//images/image
  let $kw := if ($i//kw) then $i//kw else
        <kw><item>unspecified</item></kw>,
      $loc := 
        if ($i//location)
          then $i//location
          else <location><item>unspecified</item></location>
  where