HTML concatenating text input with link

Question 1

You will need some javascript - here's a fiddle: http://jsfiddle.net/QGS5w/

Basically, you need to add something like the following in your head section of your page:

function clickyClick() {
    url = 'http://translate.google.com/#en/nl/' + document.getElementById("comment").value
    window.open(url, '_blank');
}

and then perhaps, for simplicity, change your link to a button:

<form>Comments:
<input type="text" name="comments" id="comment">
<br>
</form>
<button onclick="clickyClick()">Translate and verify</button>

A bare-bones complete page might look like this:

<html>
<head>
    <script type='text/javascript'>
        function clickyClick() {
            url = 'http://translate.google.com/#en/nl/' + document.getElementById("comment").value
            window.open(url, '_blank');
        }
</script>
</head>
<body>
  <form>Comments:
    <input type="text" name="comments" id="comment">
  </form>
  <br>
  <button onclick="clickyClick()">Translate and verify</button>

</body>

Question 2

You can use Javascript to get the value of the Comments section and send it to Google:

<script>
function test(){
  var yourvar= document.getElementById('comments').value;
  window.open('http://translate.google.com/#en/nl/'+yourvar, "_blank");
}
</script>

And the HTML:

<form>
  Comments: <input type="text" name="Scomments" id="comments"><br>    
</form>     
<button onclick="test()">Translate</button>

The code's a bit rough but you can edit it.