修改PHP URL参数的简单方法
How to get and change URL variable PHP
The simply, quick, fast method to set URL variable/parameter in PHP
$new_query = http_build_query(array_merge($_GET, array('newvar'=>'123')));
$new_uri = $_PHP_SELF.'?'.http_build_query(array_merge($_GET, array('newvar'=>0)));
echo "<a href = \"$uri\">Changed URI Parameter</a>";