function single_page_nav_link() {
	?>
	<div class="post_nav_link">
		<?php
		$categories = get_the_category();
		$categoryIDS = array();
		foreach ( $categories as $category ) {
			array_push( $categoryIDS, $category->term_id );
		}
		$categoryIDS = implode( ",", $categoryIDS );
		?>
		<div class="pre_post">
			<?php if (get_previous_post($categoryIDS)){previous_post_link('Prev： %link','%title',true);}else{ echo 'Prev： (无)';}?>
		</div>
		<div class="next_post">
			<?php if (get_next_post($categoryIDS)) {next_post_link('Next： %link','%title',true);}else{ echo 'Next： (无)';}?>
		</div>
	</div> <?php
}