单击按钮可使表单域可编辑

I want to know how to show form field editable on button click in PHP. Part of my view file:

<?php echo Form::label("email", "Email"); ?>
    <?php echo Form::input("email", $userdetails->email,array('disabled' => 'disabled')); ?>
   <br/>  
    <?php echo Form::label("description", "Description"); ?>
    <?php echo Form::textarea("description", $userdetails->description,array('disabled' => 'disabled')); ?>
    <br/>
    <?php echo Form::submit("submit", "Submit"); ?>
    <?php echo Form::close(); ?>
    <a href="../index"><input type="button" name="edit" value="Edit" ></a>

In the page load field should be disabled.

If the user clicks the Edit button the hidden field should turn to editable.

Mock Form

<form>
    <input id="inp" type="text" disabled>
    <input id="edit" type="button" value="Edit">
</form>

Javascript

var el = document.getElementById('edit');
el.addEventListener('click', function(){
    document.getElementById('inp').disabled = false;
});

DEMO

For usability sake, however, I suggest this:

var el  = document.getElementById('edit');
var inp = document.getElementById('inp');
el.addEventListener('click', function(){
    inp.disabled = false;
    inp.focus(); // set the focus on the editable field
});

Edited: OP commented that several elements will need to be enabled on click.

var el  = document.getElementById('edit');
var frm = document.getElementById('myform');
el.addEventListener('click', function(){
    for(var i=0; i < frm.length; i++) {
        frm.elements[i].disabled = false;

    } 
    frm.elements[0].focus(); // put focus on the first element
});

Another Demo

You can use jquery to set the disabled attribute to false

jQuery("input[name=edit]").click(function(){
   jQuery("input[name=email],input[name=description]").attr("disabled",false);
});

input[name=email] selects the email input field

input[name=description] selects the description input field