SO fiddle

Test Fiddle mainly for SO Questions

HTML

<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.4/themes/overcast/jquery-ui.css">
<button id="repbutton">repbutton</button>

JavaScript

$(document).ready(function() { 
   $("#repbutton").click(function() {
   $("#repbutton").replaceWith("<form id=\"reputation_form\" method=\"post\"> \
    Give positive reputation to <?=$reply_user['username']?> for their reply? \
    Comment: <input type=\"text\" name=\"comment\" id=\"comment\" /> \
             <input type=\"hidden\" id=\"uid\" value=\"<?=$reply_user['id']?>\"> \
             <input type=\"hidden\" id=\"rid\" value=\"<?=$replies_row['id']?>\"> \
             <input type=\"hidden\" id=\"urid\" value=\"<?=$user_row['id']?>\"> \
             <input type=\"submit\" value=\"Give Reputation\" /> \
</form> \
<div id=\"status\"> \
        <p></p> \
    </div>"); 

    });
   });