different layout in IE & FirFox

Dear all
I got a problem when I add two <div> in tpl_main_page.php
here is the code:

/**
  * prepares and displays header output
  *
  */
  if (CUSTOMERS_APPROVAL_AUTHORIZATION == 1 && CUSTOMERS_AUTHORIZATION_HEADER_OFF == 'true' and ($_SESSION['customers_authorization'] != 0 or $_SESSION['customer_id'] == '')) {
    $flag_disable_header = true;
  }
  require($template->get_template_dir('tpl_header.php',DIR_WS_TEMPLATE, $current_page_base,'common'). '/tpl_header.php');?>
<div id="mainWrapper">
<?php
  if (SHOW_BANNERS_GROUP_SET1 != '' && $banner = zen_banner_exists('dynamic', SHOW_BANNERS_GROUP_SET1)) {
    if ($banner->RecordCount() > 0) {
?>
<div id="bannerOne" class="banners"><?php echo zen_display_banner('static', $banner); ?></div>
<div id="topLinks">
<div id="qsearch">
<form name="quick_find_header" action="http://www.lixiaoya.com/index.php?main_page=advanced_search_result" method="get"><input type="hidden" name="main_page" value="advanced_search_result" /><input type="hidden" name="search_in_description" value="1" /><input type="text" name="keyword" size="6" maxlength="30" style="width: 100px" value="输入关键词"  (this.value == '输入关键词') this.value = '';"  (this.value == '') this.value = '输入关键词';" /> <input type="submit" value="搜索" style="width: 45px" /></form></div>
<div
        <?php if (EZPAGES_STATUS_HEADER == '1' or (EZPAGES_STATUS_HEADER == '2' and (strstr(EXCLUDE_ADMIN_IP_FOR_MAINTENANCE, $_SERVER['REMOTE_ADDR'])))) {
          require($template->get_template_dir('tpl_ezpages_bar_header.php',DIR_WS_TEMPLATE, $current_page_base,'templates'). '/tpl_ezpages_bar_header.php');
         } ?></div></div>
<?php
    }
  }
?>
<table width="100%" border="0" cellspacing="0" cellpadding="0" id="contentMainWrapper" summary="content">
  <tr>
<?php
if (COLUMN_LEFT_STATUS == 0 || (CUSTOMERS_APPROVAL == '1' and $_SESSION['customer_id'] == '') || (CUSTOMERS_APPROVAL_AUTHORIZATION == 1 && CUSTOMERS_AUTHORIZATION_COLUMN_LEFT_OFF == 'true' and ($_SESSION['customers_authorization'] != 0 or $_SESSION['customer_id'] == ''))) {
  // global disable of column_left
  $flag_disable_left = true;
}
if (!isset($flag_disable_left) || !$flag_disable_left) {
?>

the screenshots are as following:

1. In firefox
   

2. In IE
   

Website: https://www.lixiaoya.com

Thank you all in advance :clap:

Regards
Bruce

I don't know why you're adding DIV tags to your tpl_main_page.php.... Whatever it is, I'm sure there's a better way to achieve the same thing using CSS.