PHP + MySQL Paging

<? PHP $ conn = mysql_connect ("localhost", "root", "root"); mysql_select_db ("test", $ conn ); mysql_query ("set names 'utf-8'"); $ shownum = 4; if ($ _ Get ['gopagenum']) {$ gopagenum =$ _ Get ['gopagenum']; if ($ gopagenum <= 0) $ gopagenum = 1;} else {$ gopagenum = 1 ;} $ nowshowbeginnum = ($ gopagenum-1) * $ shownum; // index 0 calculates the first data $ sel_message = "select * From message limit $ nowshowbeginnum, $ shownum"; $ que_mes Sage = mysql_query ($ sel_message) or die ("invalid query:". mysql_error ();?> <Form action = "" method = "get"> <a href = "? Gopagenum = <? PHP echo ($ gopagenum-1);?> "> Previous page </a>: <a href = "? Gopagenum = <? PHP echo ($ gopagenum + 1);?> "> Next page </a> <br/> <? Phpwhile ($ row_message = mysql_fetch_array ($ que_message) {echo $ row_message ['id']. ":". $ row_message ['title']. ":". $ row_message ['content']. "<br>" ;}?> </Form>