Wordpress自定义php增加价值

I try wordpress query from separate php file its work good but i need query offset value from my own, how can i ?

if (!isset($_GET['startrow']) or !is_numeric($_GET['startrow'])) {
 $startrow = 0;
} else {
 $startrow = (int)$_GET['startrow'];
} 
?>

<ul>
<?php
 $posts = get_posts('numberposts=10&offset=0');
 foreach($posts as $post) {
  echo '<li><a href="' . get_permalink($post->ID) . '" title="'. $post->post_title .'" >' .   $post->post_title .'</a> </li> ';
  } ?>
</ul>

i want replace my $startrow value 'numberposts=10&offset=0' to 'numberposts=10&offset=$startrow' but this is not work

my url going like this myurl

 domain/my.php?startrow =100

You are using $startrow in single quaotes in 'numberposts=10&offset=$startrow'. PHP does not parses variables in single quotes.

Chagne

get_posts('numberposts=10&offset=0');

to

get_posts('numberposts=10&offset=' . $startrow);