Problem in highlighting display data using SELECT Statement with css class

Hi...
I have query in highlighting null data using this code:

Code:

<?php
include 'config.php';
$currentEmpID = $_SESSION['empID']; 
 
 if(!isset($_POST['Regsubmit_'])){ 
     
    $DATE1 = $_GET['Regfirstinput'];
    $DATE2   = $_GET['Regsecondinput'];
 
 $sql = "SELECT DISTINCT IF(ISNULL(a.LOG_IN), 'rdc', '') AS LOGIN_CLASS, IF(ISNULL(a.LOG_OUT), 'rdc', '') AS LOGOUT_CLASS, a.EMP_ID, CONCAT(LASTNAME, ', ' , FIRSTNAME) AS FULLNAME, a.LOG_IN, a.LOG_OUT
 FROM $ATTENDANCE.attendance_build AS a JOIN $ADODB_DB.employment em ON (a.EMP_ID = em.EMP_NO AND em.STATUS IN ('Reg Operatives', 'Reg Staff')) 
 WHERE LOG_IN BETWEEN '$DATE1' AND '$DATE2' 
 OR ISNULL(LOG_IN) OR ISNULL(LOG_OUT)";
 
    $DTR = $conn3->GetAll($sql);
    $smarty->assign('attendance', $DTR);
 }
 $smarty->display('header_att.tpl');
 $smarty->display('RegAttendance.tpl');
 $smarty->display('footer.tpl');
?> 

and here is the tpl code:

Code:

{section name=att loop=$attendance}
  <tr>
    <td colspan="2">{$attendance[att].EMP_ID}</td>
    <td colspan="2">{$attendance[att].FULLNAME}</td>  
    <td colspan="2" class="{$attendance[att].LOGIN_CLASS}">{$attendance[att].LOG_IN|date_format:"%d-%m-%Y %I:%M %p"}</td>
    <td colspan="2" class="{$attendance[att].LOGOUT_CLASS}">{$attendance[att].LOG_OUT|date_format:"%d-%m-%Y %I:%M %p"}</td> 
  </tr>
{sectionelse}
  <tr><td colspan="1">No DATA</td></tr>
{/section}

this code highlight the null value of login or logout or both.
this is the css:

Code:

.rdc {background-color:#ff0000;}

Now, I need to revised my query statement, because i have separate code for adding attendance if the employee has no attendance or no login or no logout.
I just want to happen is if the employee is already add his attendance in NRS table or should I said if the LOG_IN in attendance table is equal to TIME_IN in NRS table the data will have a color yellow.
For Example:
I have this data in attendance table:
EMP_ID = 012012
LOG_IN = NULL
LOG_OUT = 2011-12-12 13:35:00
I will his attendance in NRS table to have his attendance:
EMP_NO = 012012
TIME_IN = 2011-12-12 05:35:00
TIME_OUT = 2011-12-12 13:35:00

In my above query the LOG_IN has a background color of RED.
I want to happen is if I add his attendance in NRS the EMP_NO, LOG_IN, LOGOUT will have a color to notice that it is already have in NRS.
Because theirs a scenario that the employee has no login or no logout or both.

Feel free to ask me if my explanation is not clear to you.
Thank you in advance