จะเขียนโค้ด js ยังไงให้ดึงค่า input text ที่เรากรอกมา โดยที่ไม่ต้องกด submit แล้วให้ ช่อง checkbox ในหน้า pageนั้นเลือกตามจำนวน ค่าที่เรากรอกคะ

<?php
session_start();
session_destroy();
	
$booking = $_REQUEST['booking_name'];
$cheap = $_REQUEST['cheap'];
$chic = $_REQUEST['chic'];
$boutique = $_REQUEST['boutique'];
?>

<script language="JavaScript" type="text/javascript"> 

function checkChang(){
var t = setTimeout("document.booking.submit();",0); //2 seconds measured in miliseconds
}
</script>

<div>BOOKING PROGRAM</div>
 
  <table width="100%" border="0" cellspacing="0" cellpadding="2" align="center">
        <tr>
      <td height="35" colspan="2">Reservation information</td>
      </tr>
    <tr>
      <td width="27%">Program Name:</td>
      <td width="73%"><?php echo $booking ;?></td>
    </tr>
    <tr>
      <td height="30">Price:</td>
      <td height="30">6,340 THB
		<?php
		
			if($cheap==""){
				echo "";
			}else{
			//$total1 = 6340+6304;
			//$total2 = 6340+4250;
			//$total3 = 6340+6840;
				if($cheap=="5 Days at Bangkok 6,340 THB"){
					echo $cheap;
					echo "&nbsp;";
					//echo "<b>Totel</b>"."&nbsp;".$total1."&nbsp;"."THB";
				
				}
				else if($cheap=="5 Days at Chaing Mai 4,250 THB"){
				
					echo $cheap;
					echo "&nbsp;";
					//echo "<b>Totel</b>"."&nbsp;".$total2."&nbsp;"."THB";
				}else{
					echo $cheap;
					echo "&nbsp;";
					//echo "<b>Totel</b>"."&nbsp;".$total3."&nbsp;"."THB";
				
				}
			
			
			}
			
			if($chic==""){
				echo "";
			}else{
			
			echo $chic;
			echo "&nbsp;";
			//echo "<b>Totel</b>"."&nbsp;".$total2."&nbsp;"."THB";
			
			}
			if($boutique==""){
				echo "";
			}else{
			
			echo $boutique;
			echo "&nbsp;";
			//echo "<b>Totel</b>"."&nbsp;".$total3."&nbsp;"."THB";
			
			}

			
		
		?>
	  
	  </td>
    </tr>
	<!--
    <tr>
      <td height="30">Arrival date:</td>
      <td height="30"><script>DateInput('sdate', true, 'yyyy-mm-dd')</script></td>
    </tr>
    <tr>
      <td height="30" valign="top">Number of people:</td>
      <td height="30">
      	<select name="select" id="select">
        <option value="---- Selection ---">---- Selection ---</option>
      </select>
       Adult (s)<br />
       <select name="select2" id="select2">
         <option value="---- Selection ---">---- Selection ---</option>
       </select> 
       Child (3-12 years)<br />
        <select name="select3" id="select3">
          <option value="---- Selection ---">---- Selection ---</option>
        </select> 
        Infant</td>
    </tr>
    -->
<form id="booking" name="booking" action="booking_program.php?booking_name=<?= $booking ?>" method="post">
    <tr>
      <td height="30" valign="top">Excursion additional:</td>
      <td height="30">
	   1.Cheap
        <select name="cheap" id="cheap" onchange ="checkChang()">
		<option value=""  name="---- Selection ---">---- Selection ---</option>
          <option value="|&nbsp;[5 Days at Bangkok] Price 6,340 THB." name="5 Days at Bangkok">5 Days at Bangkok 6,340 THB	</option>
		   
		  <option value="|&nbsp;[5 Days at Chaing Mai] Price 4,250 THB." name=" 5 Days at Chaing Mai"> 5 Days at Chaing Mai 4,250 THB</option>
		  <option value="|&nbsp;[5 Days at Phuket] Price 6,840 THB." name="5 Days at Phuket ">5 Days at Phuket 6,840 THB 	</option>
        </select>
        <br />
	
	  2.Chic
        <select name="chic" id="chic" onchange ="checkChang()">
		<option value=""  name="---- Selection ---">---- Selection ---</option>
          <option value="|&nbsp;[5 Days at Bangkok] Price 13,475 THB	" name="5 Days at Bangkok">5 Days at Bangkok 13,475 THB	</option>
		  
		  <option value="|&nbsp;[5 Days at Chaing Mai] Price 12,375 THB" name="5 Days at Chaing Mai"> 5 Days at Chaing Mai 12,375 THB	</option>
		  <option value="|&nbsp;[5 Days at Phuket] Price 16,090 THB	" name="5 Days at Phuket">5 Days at Phuket 16,090 THB	</option>
		  
        </select>
        <br />
        3.Boutique
        <select name="boutique" id="boutique" onchange ="checkChang()">
		<option value=""  name="---- Selection ---">---- Selection ---</option>
          <option value="|&nbsp;[5 Days at Bangkok] Price 18,770 THB	" name="5 Days at Bangkok">5 Days at Bangkok 18,770 THB	</option>
		   
		  <option value="|&nbsp;[5 Days at Chaing Mai] Price 15,920 THB" name="5 Days at Chaing Mai"> 5 Days at Chaing Mai 15,920 THB	</option>
		  <option value="|&nbsp;[5 Days at Phuket] Price 21,090 THB" name="5 Days at Phuket">5 Days at Phuket 21,090 THB	</option>
        </select>
        <br />
		
	
		</td>
    </tr>
	<tr>
		<td>&nbsp;</td>
		<td>
			<input type="hidden" value="OK" name="value(Submit)" onclick="javascript:return Login_Form_Validator(document.parameter)" onmouseover="this.style.cursor='hand'"/>
			
		</td>
	
	</tr>
	<tr>
		<td>Total Price :</td>
		<td>
			<?php 
			$total = 6340;
			$total1 = 4250;
			$total2 = 6840;
			$total_1 = $total+$total;
			$total_2 = $total+$total1;
			$total_3 = $total+$total2;

			if($cheap==""){
			
			echo  number_format($total, 2   , '.'    , ','   )."&nbsp;"."THB.";
			
			}else{
			
			echo number_format($total_1, 2   , '.'    , ','   )."&nbsp;"."THB.";
			
			}
			
			
			
			
			?>
			
		</td>
	
	</tr>
	</form>
  </table>