php - Javascript:当某些内容有效时在表单中显示元素

Question

当表单中的内容经过验证时，如何显示元素？

这是我的一些代码:

注册.php

<div  class="wrapper">
   <div class="error-div" id="zipcode-error" ></div>
   <label>Zip code:</label>
   <input type="text" class="input" name="zipcode" id="zipcode" />
</div>

 <!-- this div is hidden, it can only be seen when zip code is validated -->
 <div  class="wrapper" id="city-wrapper" >
    <div class="error-div" id="city-error" ></div>
        <label>City:</label>
        <input type="text" class="input" name="city" id="city" >
 </div>
 <!-- this div is hidden, it can only be seen when zip code is validated -->

signup_validation.js

$('#zipcode').keyup(function() {
    $.post('action/validate_signup.php?key=zipcode', { zipcode: $(this).val() }, 
     function(result){
     $('#zipcode-error').html(result).show("slow");
    });

});

validate_signup.php

  if(isset($_POST['zipcode'])){
    $zip = $_POST['zipcode'];
    if(empty($zip)){
       echo "*Zipcode required!";
    }elseif( (strlen($zip)<5) OR (strlen($zip)>5)){
       echo "*Must be 5 digit!";
    }elseif(!is_numeric($zip)){
       echo "Must be numeric!";
    }else{
       $query = mysql_query("SELECT * FROM zip_codes WHERE zip = '{$zip}'");
       $found_zip = mysql_num_rows($query);
       if($found_zip =1){
         echo "<img src='images/check.jpg' /><input type = 'hidden' name='show-city' id='show-city' />";
       } else{
         echo "Zip not found";
       }

    }

 }

验证邮政编码后，我想显示城市 div，但我不知道如何显示。

情况是这样的:用户必须输入他/她的有效邮政编码，一旦通过验证，隐藏的 div 就会出现并在提供的文本字段中显示它对应的城市。

Answer 1

if($found_zip =1){
         echo "found||<img src='images/check.jpg' /><input type = 'hidden' name='show-city' id='show-city' />";
       } else{
         echo "error||error";
       }
//then ur js
$('#zipcode').blur(function() {
    var zip = $(this).val();
    $.post('action/validate_signup.php?key=zipcode', { zipcode: zip }, 
     function(result){
     var respArr = result.split("||");
      if("error" ==respArr[0]) {
        $('#zipcode-error').html(result).show("slow");
      }
      else {
        //show your hidden div here
        $("#urHidden").show("slow");
      }
    });

});