Trying this a number of ways, this header redirect basically directs but what syntax could be used to pass the variable on as well?

PHP Code:
 coming from:
https://www.site.com/page1.php?val=10
 
 
if($row_query['colA']<>'1')
header("Location: https://www.site.com/page2.php?val='.$_GET_VARS['val'].'"); 
elseif(
$row_query['colA']=='1')
header("Location: https://www.site.com/page3.php?val='.$_GET_VARS['val'].'");