php+ajax无刷新实现省、地、市三级联动二

$conn=mysql_connect("localhost","root","2328725");
mysql_select_db("novel");
mysql_query("set names 'utf8'");
if($provincecode!=""&&$provincecode!=650000&&$provincecode!=710000&&$provincecode!=810000&&$provincecode!=820000&&$provincecode!=110000&&$provincecode!=120000&&$provincecode!=310000&&$provincecode!=500000){
  $sql="select * from city where provincecode=$provincecode";
  $result=mysql_query($sql);
  echo "\n";
  echo "请选择城市\n";
  while($row=mysql_fetch_row($result)){
   echo "$row[2]\n";
  }
  echo "\n";
}

if($citycode!=""){
  $sql="select * from area where citycode=$citycode";
  $result=mysql_query($sql);
  echo "\n";
  echo "请选择县\n";
  while($row=mysql_fetch_row($result)){
   echo "$row[2]\n";
  }
  echo "\n";
}
?>