function changeMonth()
{
  document.location.href = './?' + document.forms.searchform.month.options[document.forms.searchform.month.selectedIndex].value;
}

function changeRegion()
{
  document.location.href = './?' + document.forms.searchform.region.options[document.forms.searchform.region.selectedIndex].value;
}

function changeType()
{
  document.location.href = './?' + document.forms.searchform.type.options[document.forms.searchform.type.selectedIndex].value;
}

function changeTopic()
{
  document.location.href = './?' + document.forms.searchform.topic.options[document.forms.searchform.topic.selectedIndex].value;
}