datediff

//..
$tanggal=$_POST['thn_minta'].'-'.$_POST['bln_minta'].'-'.$_POST['tgl_minta'];
$sql="SELECT * FROM inbox WHERE DATEDIFF(`ReceivingDateTime`,'$tanggal')=0 ORDER BY ID DESC";
$result=mysql_query($sql);
if($result=mysql_query($sql)){
  if(mysql_num_rows($result)){
    $i=0;
    while($row=mysql_fetch_array($result)){
      $cell[$i][0]=date('d M Y',strtotime($row['ReceivingDateTime']));
      $cell[$i][1]=date('H:i',strtotime($row['ReceivingDateTime']));
      $cell[$i][2]=$row['SenderNumber'];
      $cell[$i][3]=$row['TextDecoded'];
      $i++;
    }
  } else{
    exit('no record found');
  }
} else{
  exit('check your sql query');
}
//...