Change a navigation bar label in ProBid?

Hi, all.  I'm new and admit I know nothing about what I'm trying to do.  I'm using an older version of ProBid (v5.23) and would like to change the "Sell" link to read "Offer".

In exploring, I've come to the file "public_html/themes/v5/header.php".  It looked like all I needed to do was change line 195 from [Cap_sell] to [Cap_offer], but, when I do that, the label disappears completely leaving it blank.

Is there an easy way for me to make this work?  Any guidance would be humbly appreciated!

      <tr class="mainmenu" bgcolor="#1863BD" align="center">

        <td style="border-bottom: 2px solid #003C85;"> <a href="<?=$path;?>index.php">

          <?=$lang[Cap_home];?>

          </a> </td>

        <? if ($showSell=="Y") { ?>

        <td style="border-bottom: 2px solid #003C85;"> <a href="<?=$btn2_link;?>">

          <?=$lang[Cap_sell];?>

          </a> </td>

        <? } ?>

You'll need to print_r($lang); to see what index (if any) contains the value you're trying to echo. Beyond that, there is no way to tell from that code.

Ok.  I'll work on that.  Thank you so much for trying to help so quickly.