$extra_columns[]=array('tagname'=>'asn', 'header'=>'AS', 'source'=>'tophat', 'type'=>'string', 'title'=>'AS Number', 'fetched'=>false);
$extra_columns[]=array('tagname'=>'city', 'header'=>'LCY', 'source'=>'tophat', 'type'=>'string', 'title'=>'City', 'fetched'=>false);
$extra_columns[]=array('tagname'=>'region', 'header'=>'LRN', 'source'=>'tophat', 'type'=>'string', 'title'=>'Region', 'fetched'=>false);
$extra_columns[]=array('tagname'=>'country', 'header'=>'LCN', 'source'=>'tophat', 'type'=>'string', 'title'=>'Country', 'fetched'=>false);
$extra_columns[]=array('tagname'=>'continent', 'header'=>'LCT', 'source'=>'tophat', 'type'=>'string', 'title'=>'Continent', 'fetched'=>false);
//$extra_columns[]=array('tagname'=>'hopcount', 'header'=>'HC', 'source'=>'tophat', 'type'=>'sortAlphaNumericTop', 'title'=>'Hop count from reference node', 'fetched'=>false);
$extra_columns[]=array('tagname'=>'asn', 'header'=>'AS', 'source'=>'tophat', 'type'=>'string', 'title'=>'AS Number', 'fetched'=>false);
$extra_columns[]=array('tagname'=>'city', 'header'=>'LCY', 'source'=>'tophat', 'type'=>'string', 'title'=>'City', 'fetched'=>false);
$extra_columns[]=array('tagname'=>'region', 'header'=>'LRN', 'source'=>'tophat', 'type'=>'string', 'title'=>'Region', 'fetched'=>false);
$extra_columns[]=array('tagname'=>'country', 'header'=>'LCN', 'source'=>'tophat', 'type'=>'string', 'title'=>'Country', 'fetched'=>false);
$extra_columns[]=array('tagname'=>'continent', 'header'=>'LCT', 'source'=>'tophat', 'type'=>'string', 'title'=>'Continent', 'fetched'=>false);
//$extra_columns[]=array('tagname'=>'hopcount', 'header'=>'HC', 'source'=>'tophat', 'type'=>'sortAlphaNumericTop', 'title'=>'Hop count from reference node', 'fetched'=>false);