Adding and getting another new textbox if select dropdown in HTML PHP -

current code snippets

html

<form action="" method="post"> <select name="particulars"> <option value="username">username</option> <option value="email">email</option> <option value="address">address</option> </select> <input type="submit" name="submit" value="get selected values" /> </form> 

php

<?php if(isset($_post['submit'])){ $selected_val = $_post['particulars'];  // storing selected value in variable echo $selected_val;  // displaying selected value } 

so example, if select username, want new text box come out can type in value inside , submit, there way can it? able echo out value, not brand new text box. sorry, english not first language, thank much! :)

i keep updating , showing i've done here.

i suggest use js.

in html

<form action="test.php" method="post">     <select name="particulars">         <option value="username">username</option>         <option value="email">email</option>         <option value="address">address</option>     </select>     <!--username textfield-->     <input name="username" type="text" style="display: none">     <input type="submit" name="submit" value="get selected values" /> </form> 

suggested js

//jquery <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.8/jquery.min.js"></script>  <script type="text/javascript"> //to show if default option username selected $(document).ready(function(){     if($('select[name=particulars]').val() == "username"){         $('input[name=username]').show();     } });  //with changing dropdownlist, if username selected text field appear. $('select[name=particulars]').on('change', function(){     if($(this).val() == "username"){         $('input[name=username]').show();     }else {         $('input[name=username]').hide().val('');     } }); </script> 

in test.php

if(isset($_post['submit'])){     $selected_val = $_post['particulars'];  // storing selected value in variable     echo $selected_val;  // displaying selected value      if(isset($_post['username'])){ //added         echo "user nmae: " . $_post['username'];     } } 

hope you.