agan2 para mastah sql dan php tolong bantuannya
ane ada file php yg kl di eksekusi ngeluarin error "Query was empty"

begini code nya :

<?php

require 'sistem/config.php';
sambung();

$sql='';
$sql1='';
$sql2='';
$cek = '';
$tgl_entry = '';
$bln_entry = '';
$thn_entry = '';
$tgl_srt = '';
$bln_srt = '';
$thn_srt = '';
$no_srt = '';
$kla = '';
$indeks = '';
$asal_srt = '';
$peri_srt = '';
$jumlah = '';
$asli = '';
$no_lemari = '';
$nm_boks = '';
$run ='';

if (isset($_GET['run'])) $linkchoice=$_GET['run'];
else $linkchoice='';

switch($linkchoice){

case 'simpan' :
Input();
break;
case 'hapus' :
Hapus($_GET['arg']);
break;


}


$tgl_entry = $_POST['tgl_entry'];
$bln_entry = $_POST['bln_entry'];
$thn_entry = $_POST['thn_entry'];
$tgl_srt = $_POST['tgl_srt'];
$bln_srt = $_POST['bln_srt'];
$thn_srt = $_POST['thn_srt'];
$no_srt = $_POST['no_srt'];
$kla = mysql_real_escape_string($_POST['klasifikasi']);
$indeks = mysql_real_escape_string($_POST['indeks']);
$asal_srt = mysql_real_escape_string($_POST['asal_srt']);
$peri_srt = mysql_real_escape_string($_POST['peri_srt']);
$jumlah = mysql_real_escape_string($_POST['jumlah']);
$asli = mysql_real_escape_string($_POST['keaslian']);
$no_lemari = mysql_real_escape_string($_POST['no_lemari']);
$nm_boks = mysql_real_escape_string($_POST['nm_boks']);




if ($run=='simpan') {

$sql = "INSERT INTO surat VALUES(NULL,'$thn_entry-$bln_entry-$tgl_entry','$thn_srt-$bln_srt-$tgl_srt','$no_srt','$kla','$indeks','$asal_srt','$peri_srt','$jumlah','$asli','$no_lemari','$nm_boks');";

}
else
{
$result = mysql_query($sql) or die ("Error in query: $sql " . mysql_error());
}
echo "<form action=\"Administrasi.php\" method=\"get\"><input type=\"submit\" value=\"Kembali\"></form></center>";
mysql_close();
?>