[jQuery] How to deal with running id fields?

[TeNDoLLA]

I have this code for jquery
$(function() {
        $('#test').live('click', function() {
                $('#test').after('<p>Hello world!</p>');
        });
});

and this for php part
foreach ($out as $key => $value)
{
        $i = 0;
        echo $value['name'] . ' : <input id="test'. $i .'" type="text"
name="'. $key .'" /><br>';
        $i++;
}

So I have input fields with running ID's. The question is how can I
get the text added under the field that was clicked ? And if it has
already been added it should not add the text again.