Question: I was trying to figure out how to auto-populate the input value base on what was entered in another input field using javascript. Here's my code:

```
<script>
add = document.getElementById('address').value;
city = document.getElementById('city').value;
state = document.getElementById('state').value;
zip = document.getElementById('zip').value;
compAdd = add+" "+city+" "+state+" "+zip;
function showAdd(){
    document.getElementById('shipadd1').value=compAdd;
    document.getElementById('add1').innerHTML=compAdd;
}
</script>

<form action="" onchange="showAdd();">

Home Address: <input id="address" name="address" type="text"  /><br/>
Apt or Suite Number: <input id="suite" name="suite" type="text" /><br/>
City/Town: <input id="city" name="city" type="text" /><br/>
State:<select id="state" name="state" value="">...</select><br/>
Zip:<input id="zip" name="zip" type="text" value=""/><br/>

<p> Select Shipping Address Below: </p>

<input type="checkbox" id="shipping-address-1" name="address1" value=""><span id="shiadd1">(Print auto-populated shipping address here...)</span>

<input type="checkbox" id="shipping-address-2" name="address2" value="">ABC Corp 123 Main Street, My City, State Zip
</form>

```

Answer: 
I made a general example : 

**HTML**

```
<input type="text" class="first">
<input type="text" class="second">

```

**javascript**

```
$(".first").on('keyup',function(){
    $(".second").val($(this).val());
});

```

<http://jsfiddle.net/fmdwv/1/>

For your purpose : 

```
$("#address").on('change', function(){
  $("#shipping-address-1").val($(this).val());
});

```
Create simple html file with two input text box. The first input text box will take the input from the user about a date format and second input text box will display the current date on this format.
After the completion of first step, implement date selection library to select a date and format it according to the user input given in first input text b