Unable to Pass Values from One PHP Page to Another

There is similar code in the application that works in this same fashion, but my addition is not working. I can get the search page to pop-up in a new window, but when I select the group to pass to the form page and display the pop-up window will not close or populate the form field on the add form page. Any help would be appreciated.

ADD Form PHP Page Want to hide a readonly form field for a group name and display a button to search group listing from another page.

Form Field Page HTML Code

 <div class="form-group">
 <label class="col-sm-3 control-label" for="groupId">Group *</label>
 <div class="col-sm-6" id="div_gr_name" style="<?php if ($gr_id < 1) {?>      display:none <?php } else { ?> display:inline <?php } ?>">>
 <input type='text' name='gr_name' class='span2 form-control' placeholder="Search Group Name" value="<?php if ($gr_id != -1) {echo $gr_name;} else {echo '';} ?>"  id='gr_name' readonly='true' required/>
 </div>
 <div class="col-sm-2" style = "<?php if ($gr_id > 1) {?> display:none <?php } else { ?> display:inline <?php } ?>">
 <button type="button" class="btn btn-primary" onclick='OpenPopup()'>Search</button>
 </div>
 <div>
 <span id='paientNameMissing'></span>
 </div>
 </div>

Javascript OpenPopup from footer page

 function OpenPopup() {
 try {
    window.open("searchgroup.php", "_blank", "width=850,height=500,scrollbars=yes,resizable=yes");
  }

 catch (ex) {
     alert(ex);
 }

 finally {
     event.cancelBubble = true;
     event.returnValue = false;
     return false;
  }
 }

Searchgroup Selection PHP Page

Group Selection Page PHP & HTML Code

    //retrieve our table contents
 while($row=mysql_fetch_array($rs)){
    extract($row);
            //creating new table row per record
                    echo "<tr>
                        <td>{$gr_name}</td>
                        <td>{$gr_leadername}</td>
                        <td>{$gr_leadcontact}</td>
                        <td>{$gr_leademail}</td>
                        <td>";?><a href='#' onclick="select_group('<?php echo $gr_id ?>', '<?php echo mysql_real_escape_string($gr_name); ?>') ">Select</a><?php echo "</td>
                    </tr>";
 }
            //end table
                echo "</tbody>
            </table>
        </div>";
 }

Select Group javascript function

 function select_group( id, name ){
 var selvalue = id;
 var selvalue1 = name;
 window.opener.document.getElementById('gr_id').value = selvalue;
 window.opener.document.getElementById('gr_name').value = selvalue1;

 if (id!=0) {
window.opener.document.getElementById('div_gr_name').style.display = "inline";
 }

 else {
 window.opener.document.getElementById('div_gr_name').style.display = "none";
 }

 window.close();
 }