/**
	 * Creates links to pages.
	 * 
	 * @param	integer	$page_current The current page number.
	 * @param	integer	$page_total The total number of pages.
	 * @return 	string	HTML-code.
	 */
	function get_page_nav($page_current, $page_total)
	{
		$ar_pages = array();
		/* HTML-tag to select the current page */
		$str_tag = 'strong';
		/* Language strings */
		$str_page_prev = 'Предыдущая';
		$str_page_next = 'Следующая';
		/* String placed between the first and last page numbers */
		$str_more = '..';
		/* String to separate page numbers */
		$str_d = $this->sys['char_split_pages'];
		/* URL for paging */
		$str_url = 'index.php?book='.$this->gv['book'].'&page=%d';
		
		/* The number of links to pages displayed before and after the current page. 1 2 (3) 1 2 */
		$int_max = 2;
		$cnt_new = $page_current;
		$cnt_max = $page_current + $int_max;
		$cnt_min = $page_current - $int_max;
		/* Fix the maximum number of pages */
		if ($cnt_max > $page_total)
		{
			$cnt_max = $page_total;
		}
		/* First page */
		if ($cnt_min > 1)
		{
			$ar_pages[] = '<a href="'.sprintf($str_url, 1).'">1</a>';
			$ar_pages[] = $str_more;
		}
		/* For each page number */
		for ($i = 1; $i <= $page_total; $i++)
		{
			if ( ($i >= $cnt_min && $i <= $cnt_max) )
			{
				if ($i == $page_current)
				{
					$ar_pages[] = '<a href="'.sprintf($str_url, $i).'"><'.$str_tag.'>'.$i.'</'.$str_tag.'></a>';
				}
				else
				{
					$ar_pages[] = '<a href="'.sprintf($str_url, $i).'">'.$i.'</a>';
				}
			}
			$cnt_new++;
		}
		/* The last page */
		if ($cnt_max > 1 && ($page_current + $int_max) < $page_total)
		{
			$ar_pages[] = $str_more;
			$ar_pages[] = '<a href="'.sprintf($str_url, $page_total).'">'.$page_total.'</a>';
		}
		/* Links to Next/Prev pages */
		if ($page_current > 1)
		{
			$ar_pages[] = '<a href="'.sprintf($str_url, ($page_current - 1) ).'">'.$str_page_prev.'</a>';
		}
		if ($page_current < $page_total)
		{
			$ar_pages[] = '<a href="'.sprintf($str_url, ($page_current + 1) ).'">'.$str_page_next.'</a>';
		}
		return implode($str_d, $ar_pages);
	}