รบกวนพี่ๆหน่อยครับ ผมมีคำถามหลายคำถาม รบกวนพี่ๆเข้ามาตอบทีครับ

<?php
	session_start();
	if($_SESSION['Memid'] == "")
	{
		echo "Please Login!";
		exit();
	}
	if($_SESSION['Memid'] == "=>1")
	{
		echo "This page for member only!";
		exit();
	}	
	mysql_connect("localhost","root","root");
	mysql_select_db("orderdb");
	$strSQL = "SELECT * FROM member WHERE Memid = '".$_SESSION['Memid']."' ";
	$objQuery = mysql_query($strSQL);
	$objResult = mysql_fetch_array($objQuery);
?>
 <form name="form1" method="post" action="save_profile.php">
 <br/> <font size="5"><strong>Edit Profile</strong></font> <br/><br/>
  <center><table width="416" height="467" border="1" style="width: 400px">
    <tbody>
      <tr>
        <td width="125" height="40" bgcolor="#333333"> &nbsp;MemberID</td>
        <td width="180" bgcolor="#333333">
           &nbsp;<?php echo $objResult["Memid"];?>
        </td>
      </tr>
      <tr>
        <td height="41" bgcolor="#333333"> &nbsp;Username</td>
        <td bgcolor="#333333">
           &nbsp;<?php echo $objResult["Username"];?>
        </td>
      </tr>
      <tr>
        <td height="48" bgcolor="#333333"> &nbsp;Password</td>
        <td bgcolor="#333333"> &nbsp;<input name="txtPassword" type="Password" id="txtPassword" value="<?php echo $objResult["Password"];?>">
        </td>
      </tr>
      <tr>
        <td height="57" bgcolor="#333333"> &nbsp;Confirm Password</td>
        <td bgcolor="#333333"> &nbsp;<input name="txtConPassword" type="Password" id="txtConPassword" value="<?php echo $objResult["Password"];?>">
        </td>
      </tr>
      <tr>
        <td height="41" bgcolor="#333333">&nbsp;Name</td>
        <td bgcolor="#333333"> &nbsp;<input name="txtName" type="text" id="txtName" value="<?php echo $objResult["Name"];?>"></td>
      </tr>
      	<td height="41" bgcolor="#333333">&nbsp;Address</td>
        <td bgcolor="#333333"> &nbsp;<textarea name="txtAddress" value="<?php echo $objResult["Address"];?> "/></textarea></td>
      </tr>
      <tr>
      <td height="41" bgcolor="#333333">&nbsp;Tel</td>
        <td bgcolor="#333333"> &nbsp;<input name="txtTel" type="text" id="txtTel" value="<?php echo $objResult["Tel"];?>"></td>
      </tr>
      <tr>
      <td height="41" bgcolor="#333333">&nbsp;Email</td>
        <td bgcolor="#333333"> &nbsp;<input name="txtEmail" type="text" id="txtEmail" value="<?php echo $objResult["Email"];?>"></td>
      </tr>  
      
      

    
  </table></center> 
  <br>
  <input name="b2" value="Reset"type="Reset"/>
  <input type="submit" name="Submit" value="Save">
</form>

<?php
	session_start();
	if($_SESSION['Memid'] == "")
	{
		echo "Please Login!";
		exit();
	}
	mysql_connect("localhost","root","root");
	mysql_select_db("orderdb");
	
	if($_POST["txtPassword"] != $_POST["txtConPassword"])
	{
		echo "Password not Match!";
		exit();
	}
	$strSQL = "UPDATE member SET Password = '".trim($_POST['txtPassword'])."' 
	,Name = '".trim($_POST['txtName'])."',Tel = '".trim($_POST['txtTel'])."',Email = '".trim($_POST['txtEmail'])."',Address = '".trim($_POST['txAddress'])."' WHERE Memid = '".$_SESSION["Memid"]."' ";
	$objQuery = mysql_query($strSQL);
?>
<?	if($_SESSION["Memid"] == "=>1") ?>
	
	<script>
	alert("Save Completed");
	window.location="profile.php";
	</script>

<?php
	session_start();
	if($_SESSION['Memid'] == "")
	{
		echo "Please Login!";
		exit();
	}

	if($_SESSION['Position'] != "user")
	{
		echo "This page for User only!";
		exit();
	}	
	
	mysql_connect("localhost","root","root");
	mysql_select_db("orderdb");
	$strSQL = "SELECT * FROM member WHERE Memid = '".$_SESSION['Memid']."' ";
	$objQuery = mysql_query($strSQL);
	$objResult = mysql_fetch_array($objQuery);
?>
<?
require("connect.php");
connectdb("orderdb");
$strSQL = "select orders.orderid as Orderid,Orderdate,product.Pid as Pid,Pname,Price,Qty,Total,Name,Status from member,orders,orderdetail,product where member.memid = orders.Memid and orders.Orderid = orderdetail.Orderid and orderdetail.Pid = product.Pid";
mysql_query("set names tis620");
$objQuery = mysql_query($strSQL);
?>


<p align="center">
</p>
<table width="800" height="239" border="1" align="center" cellpadding="0" cellspacing="0">
  <td width="131" height="64" align="center" valign="middle" bgcolor="#666666">เลขที่ใบสั่งซื้อ</td>
<td width="107" align="center" valign="middle" bgcolor="#666666">วันที่สั่งซื้อ</td>

<td width="147" align="center" valign="middle" bgcolor="#666666">ชื่อสินค้า</td>
<td width="67" align="center" valign="middle" bgcolor="#666666">ราคา</td>
<td width="77" align="center" valign="middle" bgcolor="#666666">จำนวน</td>
<td width="95" align="center" valign="middle" bgcolor="#666666">ราคารวม</td>

<td width="160" align="center" valign="middle" bgcolor="#666666">สถานะการชำระเงิน</td>
</tr>
<?
while($objResult = mysql_fetch_array($objQuery)){
	?>
    <tr>
    <td height="173" align="center" valign="middle" bgcolor="#666666"><? echo $objResult['Orderid']?></td>
    <td align="center" valign="middle" bgcolor="#666666"><? echo $objResult['Orderdate']?></td>
    
    <td align="center" valign="middle" bgcolor="#666666"><? echo $objResult['Pname']?></td>
    <td align="center" valign="middle" bgcolor="#666666"><? echo $objResult['Price']?></td>
    <td align="center" valign="middle" bgcolor="#666666"><? echo $objResult['Qty']?></td>
    <td align="center" valign="middle" bgcolor="#666666"><? echo $objResult['Total']?></td>
    
    <td align="center" valign="middle" bgcolor="#666666">
    <? if($objResult['Status']==1) {?>
    <? echo ยังไม่ชำระเงิน?>
    <? }else { ?>
      <? echo ชำระเงินแล้ว ?>
      <? } ?>
      </td>
      </tr>
      <? } ?>
      </table>

<?php
	session_start();
	if($_SESSION['Memid'] == "")
	{
		echo "Please Login!";
		exit();
	}
	if($_SESSION['Memid'] == "=>1")
	{
		echo "This page for member only!";
		exit();
	}
	
?>
<?php 
$serverName = "localhost";
$userName = "root";
$userPassword = "root";
$dbName = "orderdb";

$objCon = mysqli_connect($serverName,$userName,$userPassword,$dbName);
if (!$objCon) {
    echo $objCon->connect_error;
    exit();
}
?>
<?php
ob_start();
session_start();
	
if(!isset($_SESSION["intLine"]))
{
	 $_SESSION["intLine"] = 0;
	 $_SESSION["strPid"][0] = $_GET["Pid"];	
}
else
{
	$key = array_search($_GET["Pid"], $_SESSION["strPid"]);
	if((string)$key != "")
	{	
	}
	else
	{
		 $_SESSION["intLine"] = $_SESSION["intLine"] + 1;
		 $intNewLine = $_SESSION["intLine"];
		 $_SESSION["strPid"][$intNewLine] = $_GET["Pid"];
	}	
}
?>

<center><table width="449" height="754" border="10">
<?php

  for($i=0;$i<=(int)$_SESSION["intLine"];$i++)
  {
	  if($_SESSION["strPid"][$i] != "")
	  {
		$strSQL = "SELECT * FROM product WHERE Pid = '".$_SESSION["strPid"][$i]."' ";
		$objQuery = mysqli_query($objCon,$strSQL);
		$objResult = $objResult = mysqli_fetch_array($objQuery,MYSQLI_ASSOC);

 		
	  ?>
  <tr>
    <td width="447" height="269" align="center" valign="middle" bgcolor="#FFFFFF"><img src="<? echo $objResult["Pic"]?>" width="250" height="220"/></td>
  </tr>
  <tr>
    <td height="56" align="center" valign="middle" bgcolor="#666666"><font size="5"><font color="#FC0"><strong><?php echo $objResult["Pname"];?></strong></font></font></td>
  </tr>
  <tr>
    <td height="261" align="center" valign="middle" bgcolor="#666666"><?php echo $objResult["Detail"];?></td>
  </tr>
  <tr>
    <td height="53" align="right" valign="middle" bgcolor="#666666"><?php echo $objResult["Price"];?>.Baht</td>
  </tr>
  <tr>
    <td height="78" align="center" valign="middle" bgcolor="#666666"><a href="ordercart.php?Pid=<? echo $objResult["Pid"]?>">สั่งซื้อสินค้า <img src="Picweb/pic cpu/cart.jpg" width="105" height="70" /></a></td>
  </tr>
 
  	  <?php
	  }
	  
  }
  ?>
</table></center>