<!-- buat form search -->
<form action="" method="get" id="form1">
	Kecamatan:
	<select name="kec" id="kec" onchange="document.getElementById('form1').submit()">
		<option value=""></option>
		<?php
		$queryKec = mysql_query("select * from tbl_1");
		while($kec = mysql_fetch_array($queryKec)){
			echo '<option value="'.$kec['id_kec'].'">'.$kec['nama_kec'].'</option>';
		}
		?>
	</select>
	Desa:
	<select name="desa" id="desa">
		<option value=""></option>
		<?php
		$sql = "select * from tbl_2";
		if(isset($_GET['kec']) && $_GET['kec']){
			$sql .= " where id_kec='".$_GET['kec']."'";
		}
		$queryDesa = mysql_query($sql);
		while($desa = mysql_fetch_array($queryDesa)){
			echo '<option value="'.$desa['id_desa'].'">'.$desa['nama_desa'].'</option>';
		}
		?>
	</select>
	NIK: <input type="text" name="nik"/>
	Nama: <input type="text" name="nama"/>
	<input type="submit" name="search" value="Search"/>
</form>
<?php
// searching
$sql = "select * from tbl_3 where 1=1";
if(isset($_GET['search'])){
	if(isset($_GET['kec']) && $_GET['kec']){
		$sql .= " and id_kec='".$_GET['kec']."'";
	}
	if(isset($_GET['desa']) && $_GET['desa']){
		$sql .= " and id_desa='".$_GET['desa']."'";
	}
	if(isset($_GET['nik']) && $_GET['nik']){
		$sql .= " and nik='".$_GET['nik']."'";
	}
	if(isset($_GET['nama']) && $_GET['nama']){
		$sql .= " and nama LIKE '%".$_GET['nama']."%'";
	}
}
$query = mysql_query($sql);
while($data = mysql_fetch_array($query)){
	// tampilkan data hasil searching
	// tolong buat sendiri
	// misal:
	echo $data['nama'].'<br/>';
}