ช่วยดูโค้ดค้นหา 3 textbox หลายเงื่อนไข ให้หน่อยครับ (ช่วยทีครับ)

mysql_select_db($database_ConnectSW, $ConnectSW);
	$strSQL1 = "SELECT * FROM datacar WHERE 1";
	if($_POST["ddlGeo"] != "")
	{
	$strSQL1 = "SELECT * FROM datacar WHERE data_brand LIKE '".$_POST["ddlGeo"]."'";
	}
	if($_POST["ddlGeo"] != "" && $_POST["ddlProvince"] != "")
	{
		$strSQL1 = "SELECT * FROM datacar WHERE data_brand LIKE '".$_POST["ddlGeo"]."' AND data_gene LIKE '".$_POST["ddlProvince"]."'";
	}
	if($_POST["ddlGeo"] != "" && $_POST["ddlProvince"] != "" && $_POST["ddlAmphur"] != "")
	{
		$strSQL1 = "SELECT * FROM datacar WHERE data_brand LIKE '".$_POST["ddlGeo"]."' AND data_gene LIKE '".$_POST["ddlProvince"]."' AND data_year LIKE '".$_POST["ddlAmphur"]."'";
	}
	
$Recordset1 = mysql_query($strSQL1, $ConnectSW) or die(mysql_error());
$row_Recordset1 = mysql_fetch_assoc($Recordset1);
$totalRows_Recordset1 = mysql_num_rows($Recordset1);
			if($row_Recordset1){
}else{
	 $msg1 = "ไม่พบข้อมูลที่ค้นหา";
}
<script language = "JavaScript">

		//**** List Province (Start) ***จังหวัด//
		function ListProvince(SelectValue)
		{
			frmMain.ddlProvince.length = 0
			frmMain.ddlAmphur.length = 0
			//*** Insert null Default Value ***//
			var myOption = new Option('<-- เลือกแบบ(รุ่น) -->')
			frmMain.ddlProvince.options[frmMain.ddlProvince.length] = myOption
			var myOption = new Option('<-- เลือกปี -->')
			frmMain.ddlAmphur.options[frmMain.ddlAmphur.length] = myOption
			<?php
			$intRows = 0;
			$strSQL1 = "SELECT * FROM datacar GROUP BY data_gene HAVING (COUNT(data_gene) > 0)";
			$objQuery1 = mysql_query($strSQL1) or die ("Error Query [".$strSQL1."]");
			$intRows = 0;
			while($objResult1 = mysql_fetch_assoc($objQuery1))
			{
			$intRows++;
			?>			
				x = <?=$intRows;?>;
				mySubList = new Array();
				
				strGroup = "<?=$objResult1["data_brand"];?>";
				strValue = "<?=$objResult1["data_gene"];?>";
				mySubList[x,0] = strGroup;
				mySubList[x,1] = strValue;
				if (mySubList[x,0] == SelectValue){
					var myOption = new Option(mySubList[x,1])  
					frmMain.ddlProvince.options[frmMain.ddlProvince.length]= myOption					
				}
			<?php
			}
			?>																	
		}
		//**** List Province (End) ***//

		
		//**** List Amphur (Start) ***อำเภอ//
		function ListAmphur(SelectValue)
		{
			
		    frmMain.ddlAmphur.length = 0
			//*** Insert null Default Value ***//
			var myOption = new Option('<-- เลือกปี -->')
			frmMain.ddlAmphur.options[frmMain.ddlAmphur.length]= myOption
			
			
			<?php
			$intRows = 0;
			$strSQL1 = "SELECT * FROM datacar ORDER BY data_brand ASC";
			$objQuery1 = mysql_query($strSQL1) or die ("Error Query [".$strSQL1."]");
			$intRows = 0;
			while($objResult1 = mysql_fetch_array($objQuery1))
			{
			$intRows++;
			?>
				x = <?=$intRows;?>;
				mySubList = new Array();
				
				strGroup = "<?=$objResult1["data_gene"];?>";
				strValue = "<?=$objResult1["data_year"];?>";
				mySubList[x,0] = strGroup;
				mySubList[x,1] = strValue;			
				
				if (mySubList[x,0] == SelectValue){
					var myOption = new Option(mySubList[x,1])  
					frmMain.ddlAmphur.options[frmMain.ddlAmphur.length]= myOption					
				}
			<?php
			}
			?>																	
		}
		

</script>

<form name="frmMain" action="" target="_self" method="post"><select id="ddlGeo" name="ddlGeo" onChange = "ListProvince(this.value)">
	<option value="" ><-- เลือกยี่ห้อ --></option>
            <?php
			$strSQL1 = "SELECT DISTINCT data_brand FROM datacar ORDER BY data_brand ASC";
			$objQuery1 = mysql_query($strSQL1);
			while($objResult1 = mysql_fetch_array($objQuery1))
			{
			?>
            <option value="<?php echo $objResult1["data_brand"];?>"><?php echo $objResult1["data_brand"];?></option>
            <?php
			} 
			?> 
            </select>
            <tr>
    <th scope="col" width="50" align="left" style="color:#000">แบบ(รุ่น)</th>
    <th scope="col" width="244" align="left"><select id="ddlProvince" name="ddlProvince"  onChange= "ListAmphur(this.value)"><option value=""   ><-- เลือกแบบ(รุ่น) --></option></select><tr>
    <th scope="col" width="50" align="left" style="color:#000">ปี</th>
    <th scope="col" width="244" align="left"><select id="ddlAmphur" name="ddlAmphur" ><option value=""   ><-- เลือกปี --></option></select> 
     <th scope="col" width="50" align="left"><input name="btnsearch1" type="submit" value="search !" /></th> </form>

<?php do { ?>
      <tr>
    
            <div class="kkkk6"><a href="albumcar.dwt.php?car_id=<?php echo $row_Recordset1["car_id"];?>" class="link_12_dark_blue" style="text-decoration: none;"><span></span><img src="img-products/<?php echo $row_Recordset1['pic_car']; ?>" width="260" height="260"  /><br />
              <?php echo $row_Recordset1['data_brand']; ?> <?php echo $row_Recordset1['data_gene']; ?><br />
              ราคา<?php echo $row_Recordset1['data_pricesell']; ?>(บาท)<br />
              
            </div>
            
      </tr>
      <?php } while ($row_Recordset1 = mysql_fetch_assoc($Recordset1)); ?>

$strSQL1 = "SELECT * FROM datacar WHERE 1";
if(!empty($_POST["ddlGeo"] ))$strSQL1.=" AND data_brand LIKE '".$_POST["ddlGeo"]."'";
if(!empty($_POST["ddlProvince"] ))$strSQL1.=" AND  data_gene LIKE '".$_POST["ddlProvince"]."'";
if(!empty($_POST["ddlAmphur"] ))$strSQL1.=" AND  data_year LIKE '".$_POST["ddlAmphur"]."'";