requiring fields in ADV Guestbook 2.2

Hey guys can you help me out here? I am having problems requiring the location field in guestbook 2.2. This code is from the form.php file .

The funny thing is that I make these changes on the script and instead of it using the message for requiring I had for the first name field. It is still using the one from the lang/english.php file. So it's not recoginizing changes from either one.

Would there be another file that I am forgeting?

Thanks Jas

if(document.book.comment.value == "") {
   alert("$LANG[ErrorPost2]");
   document.book.comment.focus();
   return false;
 }

if(document.book.comment.value.length<$VARS[min_text] || document.book.comment.value.length>$VARS[max_text]) {
   alert("$LANG[ErrorPost3]");
   document.book.comment.focus();
   return false;
 }
 flag=1;
 return true;
}
function trim(value) {
 startpos=0;
 while((value.charAt(startpos)==" ")&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;(startpos<value.length)) {
   startpos++;
 }
 if(startpos==value.length) {
   value="";
 } else {
   value=value.substring(startpos,value.length);
   endpos=(value.length)-1;
   while(value.charAt(endpos)==" ") {
     endpos--;
   }
   value=value.substring(0,endpos+1);
 }
 return(value);
}
//-->
</script>
<table border="0" cellspacing="0" cellpadding="2" align="center" width="800">
  <tr>
   <td height="45" align="center"><b><font size="4" face="$VARS[font_face]" color="02566f">Post A Trade</font></b></td>
   <td height="45"> </td>
 </tr>
 <tr>
   <td valign="bottom"><font size="3" face="arial">Post your hunting or fishing trade with this form. Explain in detail what you have to offer, and what would you like in exchange for your offer. At least one side of the trade must be somehow related to fishing or hunting.</font></td></tr>

<tr><td  align="left" valign="bottom" class="font2"><br><b><img src="img/return.gif" width="10" height="10"><font face="arial" size="2">
     <a href="index.php">Back to the Trade Listings</a> | <img src="img/lock.gif" width="9" height="11"> <a href="admin.php">$LANG[BookMess5]</a></b></font></td>
 </tr>
</table>
<form method="post" action="$SELF" name="book" enctype="multipart/form-data" onsubmit="return checkForm()">
<table border="0" cellspacing="1" cellpadding="4" width="800" align="center" bgcolor="$VARS[tb_bg_color]">
  <tr>
    <td colspan="2" bgcolor="$VARS[tb_hdr_color]"><b><font size="2" face="$VARS[font_face]" color="$VARS[tb_text]">Post your trade:</font></b></td>
  </tr>
  <tr bgcolor="$VARS[tb_color_1]">
    <td width="25%" class="font1"><img src="img/user.gif" width="16" height="15">First Name:</td>
    <td><input type="text" name="name" size="42" maxlength="30"></td>
  </tr>
<tr bgcolor="$VARS[tb_color_1]">
    <td width="25%" class="font1"><img src="img/user.gif" width="16" height="15">Last Name:</td>
    <td><input type="text" name="location" size="42" maxlength="30"></td>
  </tr>

<tr bgcolor="$VARS[tb_color_1]">
    <td width="25%" class="font1"><img src="img/email.gif" width="15" height="15"> $LANG[FormEmail]:</td>
    <td><input type="text" name="email" size="42" maxlength="30"></td>
  </tr>

$OPTIONAL

<tr bgcolor="$VARS[tb_color_1]">
    <td width="25%" valign="top" class="font1">Trade Description:
    <br><br><div align="left" class="font2">$HTML_CODE<br>$SMILE_CODE<br>$AG_CODE<br><br>
     <a href="javascript:openCentered('$LANG_CODES','codes','640','450','scrollbars=yes')">$LANG[FormMess4]</a></div></td>
    <td bgcolor="$VARS[tb_color_1]"><textarea name="comment" cols="41" rows="10" wrap="VIRTUAL"></text><br>
    </td>
  </tr>
  <tr bgcolor="$VARS[tb_color_1]">
    <td width="25%"> </td>
    <td>
      <input type="submit" name="gb_action" value="$LANG[FormSubmit]" class="input" onclick="if(flag==1) return false;">