公司页面白色背景问题 data_div

<table cellspacing="0" cellpadding="0" border="0" class="main_table_layout" id="table_body">
    <tr>
      <td valign="top"><table cellspacing="0" cellpadding="0" border="0" class="main_table_layout">
          <tr class="menu_tr_height">
            <td colspan="3" valign="middle">
             
              <!-- 菜单栏 -->
              <div class="menu_div">
                <div class="menu_div_left"></div>
                <div class="menu_div_right"></div>
                <!-- 当前位置导航 -->
                <div class="pos_div"> <span id="posinfo" class="pos_span">用户 >> 修改</span> </div>
              </div></td>
          </tr>
         
          <tr>
            <td class="list_border"></td>
            <td valign="top">
<div class="data_div" id="data_div" style="height: 550px">
                <table width="100%" cellspacing="0" cellpadding="0" class="data_table">
                  <tr>
                    <td width="120" class="data_td_left">用户名：</td>
                    <td class="data_td_right"><s:textfield name="whguser.username" id="username" validate="{required:true}"></s:textfield>
                      <font class="tip_input">*</font>
                      <div id="div_username" style="vertical-align:middle;"></div></td>
                  </tr>
                  <tr>
                    <td class="data_td_left"> 真实姓名：</td>
                    <td class="data_td_right"><s:textfield type="text" name="whguser.realname" id="realname" class="txt_150" validate="{required:true}"/>
                      <font class="tip_input">*</font>
                      <div id="div_sktime" style="vertical-align:middle;"></div></td>
                  </tr>
                  <tr>
                    <td class="data_td_left"> 身份证号码：</td>
                    <td class="data_td_right"><s:textfield type="text" name="whguser.idcard" id="idcard" class="txt_150" validate="{required:true,datatype:'idcard'}"/>
                      <font class="tip_input">*</font>
                      <div id="div_address" style="vertical-align:middle;"></div></td>
                  </tr>
                  <tr>
                    <td class="data_td_left"> 手机：</td>
                    <td class="data_td_right"><s:textfield type="text" name="whguser.mobile" id="mobile" class="txt_150" validate="{required:true}"/>
                      <font class="tip_input">*</font>
                      <div id="div_address" style="vertical-align:middle;"></div></td>
                  </tr>
                  <tr>
                    <td class="data_td_left"> 家庭住址：</td>
                    <td class="data_td_right"><s:textfield type="text" name="whguser.address" id="address" class="txt_150" validate="{required:true}"/>
                      <font class="tip_input">*</font>
                      <div id="div_address" style="vertical-align:middle;"></div></td>
                  </tr>
                 
                </table>
                <table width="100%" cellspacing="0" cellpadding="0">
                  <tr>
                    <td align="center" height="40px;"><input type="button" class="buttonSty1" name="okBtn" id="okBtn" onClick="updateWhgUser()" value="确 定" />
                      &nbsp;&nbsp;
                      <input type="button" name="cancelBtn" id="cancelBtn" class="buttonSty1" value="返 回" onClick="history.go(-1)" />
                    </td>
                  </tr>
                </table>
              </div></td>
            <td class="list_border"></td>
          </tr>
        </table></td>
    </tr>
  </table>