Redmine

Hello,
I am trying to resize the text area in the app/views/wiki/edit.rhtml file.
this line:

<%= f.text_area_tag :reason, :nil :size =>'5x15', :class => 'wiki-edit', :accesskey => accesskey(:edit) %>

What I am tryint to get is that, if I enter only one line, the rows of the text area should be 1, and if I enter 10 (or n rows) lines of text, the text area should grow (every second) to 10 (or n rows) rows.
Similar solution is used in trac with jQuery:

<script type="text/javascript">
      jQuery(document).ready(function($) {
        $("#text").blur(function() {
          $("#scroll_bar_pos").val(this.scrollTop);
        }).get(0).scrollTop = $("#scroll_bar_pos").val();
        $("#editrows").change(function() {
          resizeTextArea("text", this.options[this.selectedIndex].value);
        });
          function autoResizeText() {
            var preview_height = $("#preview").height();
            if (preview_height)
              $("#text").height(preview_height);
          }
          autoResizeText();
          $(window).resize(autoResizeText);
          $("#text").autoPreview("/trac/ecom/wiki_render", {
              realm: "wiki", id: "Shops" 
            }, function(textarea, text, rendered) {
              $("#preview div.wikipage").html(rendered);
              autoResizeText();
          });
      });
    </script>

Could someone help me to adapt the script to my text area, please?

Thank you,
Vige