I have a FORM with 2 input fields `$first_name` and `$last_name`. 

```
<?
$first_name = get_post_meta($post->ID, 'fname', true);
$last_name = get_post_meta($post->ID, 'lname', true);

$fname_tmp = 'Foo' ; // First Name TEMP
$lname_tmp = 'Bar' ; // Last Name TEMP
?>

<input type="text" value="<? echo $first_name;?>" name="first_name" />
<input type="text" value="<? echo $last_name;?>" name="last_name" />

```

I want to add a onClick "GET/IMPORT" Button/function in this form. So if a user press this button then inputs field `first_name` should show **Foo** and `last_name` should show **Bar**

How can I do this? Using PHP?
Many thanks in advance.