Elseif isset statement

it's still at filter.. soo I've made a multi search at a web page it had several text box and date box to get used at search this is my if statement when submit button was clicked.. its fine to get elseif like that or not? coz i just can submited name,not pkt,from,and to

 <?php
                  $no = 1;
                  if (isset($_POST['cari']))
                  {
                    //search qry
                    $keyword = $_POST['keyword'];
                    $pkt = $_POST['pkt'];
                    $from = $_POST['from'];
                    $to = $_POST['to'];

                    $sql =
                    "SELECT tb_peserta.id_peserta,tb_data.nama,tb_paket.nama_paket,tb_peserta.ket,tb_peserta.waktu_awal,tb_peserta.waktu_akhir 
                    FROM tb_peserta,tb_data,tb_paket 
                    WHERE  tb_peserta.status_data_peserta='aktif'
                    AND tb_peserta.id_number=tb_data.id_number
                    AND tb_peserta.id_paket = tb_paket.id_paket  
                    AND (tb_data.nama LIKE '%$keyword%')";
                  }
                  elseif(isset($_POST['cari'])){
                    $pkt = $_POST['pkt'];
                    $sql =
                    "SELECT tb_peserta.id_peserta,tb_data.nama,tb_paket.nama_paket,tb_peserta.ket,tb_peserta.waktu_awal,tb_peserta.waktu_akhir 
                    FROM tb_peserta,tb_data,tb_paket 
                    WHERE  tb_peserta.status_data_peserta='aktif'
                    AND tb_peserta.id_number=tb_data.id_number
                    AND tb_peserta.id_paket = tb_paket.id_paket  
                    AND (tb_paket.nama_paket LIKE '%$pkt%')";
                  }
                  elseif(isset($_POST['cari'])){
                    $from = $_POST['from'];
                    $sql =
                    "SELECT tb_peserta.id_peserta,tb_data.nama,tb_paket.nama_paket,tb_peserta.ket,tb_peserta.waktu_awal,tb_peserta.waktu_akhir 
                    FROM tb_peserta,tb_data,tb_paket 
                    WHERE  tb_peserta.status_data_peserta='aktif'
                    AND tb_peserta.id_number=tb_data.id_number
                    AND tb_peserta.id_paket = tb_paket.id_paket  
                    AND (tb_peserta.waktu_awal LIKE '%$from%')";
                  }
                  elseif(isset($_POST['cari'])){
                    $to = $_POST['to'];
                    $sql =
                    "SELECT tb_peserta.id_peserta,tb_data.nama,tb_paket.nama_paket,tb_peserta.ket,tb_peserta.waktu_awal,tb_peserta.waktu_akhir 
                    FROM tb_peserta,tb_data,tb_paket 
                    WHERE  tb_peserta.status_data_peserta='aktif'
                    AND tb_peserta.id_number=tb_data.id_number
                    AND tb_peserta.id_paket = tb_paket.id_paket  
                    AND (tb_peserta.waktu_akhir LIKE '%$to%')";
                  }
                  else{
                    $sql = "SELECT tb_peserta.id_peserta,tb_data.nama,tb_paket.nama_paket,tb_peserta.ket,tb_peserta.waktu_awal,tb_peserta.waktu_akhir FROM tb_peserta,
                    tb_data,tb_paket WHERE tb_peserta.id_number=tb_data.id_number AND tb_peserta.id_paket = tb_paket.id_paket AND tb_peserta.status_data_peserta='aktif'";
                  }
                  $data = mysqli_query($conn,$sql);
                  while ($hasil=mysqli_fetch_array($data)) {
                    ?>

blah blah blah form here