สอบถาม PHP+MySQL (อัตราค่าจ้าง*วันมาทำงาน) เมื่อ Input วันทำงานแล้วจะแสดงผลลัพธ์รวมเงิน

<?php require_once('../Connections/connect.php'); ?>
<?php
if (!function_exists("GetSQLValueString")) {
function GetSQLValueString($theValue, $theType, $theDefinedValue = "", $theNotDefinedValue = "") 
{
  $theValue = get_magic_quotes_gpc() ? stripslashes($theValue) : $theValue;

  $theValue = function_exists("mysql_real_escape_string") ? mysql_real_escape_string($theValue) : mysql_escape_string($theValue);

  switch ($theType) {
    case "text":
      $theValue = ($theValue != "") ? "'" . $theValue . "'" : "NULL";
      break;    
    case "long":
    case "int":
      $theValue = ($theValue != "") ? intval($theValue) : "NULL";
      break;
    case "double":
      $theValue = ($theValue != "") ? "'" . doubleval($theValue) . "'" : "NULL";
      break;
    case "date":
      $theValue = ($theValue != "") ? "'" . $theValue . "'" : "NULL";
      break;
    case "defined":
      $theValue = ($theValue != "") ? $theDefinedValue : $theNotDefinedValue;
      break;
  }
  return $theValue;
}
}

mysql_select_db($database_connect, $connect);
$query_Recordset1 = "SELECT * FROM employee";
$Recordset1 = mysql_query($query_Recordset1, $connect) or die(mysql_error());
$row_Recordset1 = mysql_fetch_assoc($Recordset1);
$totalRows_Recordset1 = mysql_num_rows($Recordset1);
?><meta http-equiv="Content-Type" content="text/html; charset=utf8" />
<style type="text/css">
<!--
.style1 {font-size: 24px}
.style2 {font-size: 18px}
-->
</style>

<form action="<?php echo $_SERVER['PHP_SELF']; ?>" method="post">

<?php

	
?>


  <p align="center" class="style1">เงินเดือนพนักงาน</p>
  <p align="center" class="style2">ประจำเดือน / ปี</p>
  <p align="center" class="style2">
    <select name="select" id="select">
      <option>มกราคม</option>
      <option>กุมพาพันธ์</option>
      <option>มีนาคม</option>
      <option>เมษายน</option>
      <option>พฤษภาคม</option>
      <option>มิถุนายน</option>
      <option>กรกฎาคม</option>
      <option>สิงหาคม</option>
      <option>กันยายน</option>
      <option>ตุลาคม</option>
      <option>พฤศจิกายน</option>
      <option>ธันวาคม</option>
                                        </select>
    <select name="select2" id="select2">
      <option>2554</option>
      <option>2555</option>
      <option>2556</option>
      <option>2557</option>
      <option>2558</option>
      <option>2559</option>
      <option>2560</option>
      <option>2561</option>
      <option>2562</option>
      <option>2563</option>
                                    </select>
  </p>


  <table width="898" border="1" align="center">
    <tr>
      <td width="52">ลำดับที่</td>
      <td width="159"><div align="center">ชื่อ </div></td>
      <td width="162"><div align="center">นามสกุล</div></td>
      <td width="150"><div align="center">แผนก</div></td>
      <td width="157"><div align="center">อัตราค่าจ้าง</div></td>
      <td width="81">วันมาทำงาน</td>
      <td width="91"><div align="center">รวมเงิน</div></td>
    </tr>
    <tr>
 

<?php
$sqltxt = "SELECT * FROM employee"; 
$db_query=mysql_db_query($db,$sql);

	$sub_total = $row_Recordset1['emp_price'] * $row_Recordset1['emp_other'] ;
	$empoth = $row_Recordset1['emp_other']; {
	echo "
		<td align=center></td>
		<td align=center>{$row_Recordset1['emp_name']}</td>
		<td align=center>{$row_Recordset1['emp_lname']}</td>
		<td align=center>{$row_Recordset1['emp_dep']}</td>
		<td align=center>{$row_Recordset1['emp_price']}</td>
     <td align=center>
	<input type=text size=10  name=$empoth value={$row_Recordset1['emp_other']} />
		</td>
      <td>$sub_total</td>
	</tr>";
	
	}
?>


    </tr>
  </table>
  <p align="center" class="style2">
    <label>
    <input type="submit" name="button" id="button" value="บันทึก" />
    </label>
    <label>
    <input type="submit" name="button2" id="button2" value="ลบข้อมูล" />
    </label>
  </p>
  <label></label>
<p>&nbsp;</p>
  <p>&nbsp;</p>
  <p align="left" class="style2">&nbsp;</p>
  <p align="left">&nbsp;</p>
  <p>&nbsp;</p>
  <p>&nbsp;</p>
  <p>&nbsp;</p>
</form>
<?php
mysql_free_result($Recordset1);
?>