จะพัฒนาระบบ Login & Register โดยแยก User กับ Admin จะต้องทำยังไงค่ะ

/********************************************************************************************************************
* This script is brought to you by Vasplus Programming Blog by whom all copyrights are reserved.
* Website: www.vasplus.info
* Email: [email protected]
* Please, do not remove this information from the top of this page.
*********************************************************************************************************************/



function vpb_users_registration() 
{
	var reg = /^([A-Za-z0-9_\-\.])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/;
	var vpb_firstname = $("#firstname").val();
	var vpb_lastname = $("#lastname").val();
	var vpb_email = $("#email").val();
	var vpb_passwd = $("#passwd").val();
	
	if(vpb_firstname == "")
	{
		$("#signup_status").html('<div class="info">Please enter your firstname in the required field to proceed.</div>');
		$("#firstname").focus();
	}
	else if(vpb_lastname == "")
	{
		$("#signup_status").html('<div class="info">Please enter your lastname to proceed.</div>');
		$("#lastname").focus();
	}
	else if(vpb_email == "")
	{
		$("#signup_status").html('<div class="info">Please enter your email address to proceed.</div>');
		$("#email").focus();
	}
	else if(reg.test(vpb_email) == false)
	{
		$("#signup_status").html('<div class="info">Please enter a valid email address to proceed.</div>');
		$("#email").focus();
	}
	else if(vpb_passwd == "")
	{
		$("#signup_status").html('<div class="info">Please enter your desired password to go.</div>');
		$("#passwd").focus();
	}
	else
	{
		var dataString = 'firstname='+ vpb_firstname + '&lastname=' + vpb_lastname + '&email=' + vpb_email + '&passwd=' + vpb_passwd + '&page=users_registration';
		$.ajax({
			type: "POST",
			url: "vpb_save_details.php",
			data: dataString,
			cache: false,
			beforeSend: function() 
			{
				$("#signup_status").html('<br clear="all"><br clear="all"><div align="left"><font style="font-family:Verdana, Geneva, sans-serif; font-size:15px; color:black;">Please wait</font> <img src="images/loadings.gif" alt="Loading...." align="absmiddle" title="Loading...."/></div><br clear="all">');
			},
			success: function(response)
			{
				var response_brought = response.indexOf('registered_successfully=yes');
				if (response_brought != -1) 
				{
					$("#signup_status").html('');
					window.location.replace(response);
				}
				else
				{
					$("#signup_status").fadeIn(1000).html(response);
				}
			}
		});
	}
}

function vpb_users_login() 
{
	var vpb_email = $("#email").val();
	var vpb_passwd = $("#passwd").val();
	
	if(vpb_email == "")
	{
		$("#login_status").html('<div class="info">Please enter your account email address to proceed.</div>');
		$("#email").focus();
	}
	else if(vpb_passwd == "")
	{
		$("#login_status").html('<div class="info">Please enter your account password to go.</div>');
		$("#passwd").focus();
	}
	else
	{
		var dataString = 'email=' + vpb_email + '&passwd=' + vpb_passwd + '&page=users_login';
		$.ajax({
			type: "POST",
			url: "vpb_save_details.php",
			data: dataString,
			cache: false,
			beforeSend: function() 
			{
				$("#login_status").html('<br clear="all"><br clear="all"><div align="left"><font style="font-family:Verdana, Geneva, sans-serif; font-size:15px; color:black;">Please wait</font> <img src="images/loadings.gif" alt="Loading...." align="absmiddle" title="Loading...."/></div><br clear="all">');
			},
			success: function(response)
			{
				var response_brought = response.indexOf('login_process_completed_successfully=yes');
				if (response_brought != -1) 
				{
					$("#login_status").html('');
					window.location.replace(response);
				}
				else
				{
					$("#login_status").fadeIn(1000).html(response);
				}
			}
		});
	}
}

<?php
/********************************************************************************************************************
* This script is brought to you by Vasplus Programming Blog by whom all copyrights are reserved.
* Website: www.vasplus.info
* Email: [email protected]
* Please, do not remove this information from the top of this page.
*********************************************************************************************************************/
session_start();
include "database_connection.php";


if(isset($_POST["page"]) && !empty($_POST["page"]))
{
	//Sign-up Page Starts here
	if($_POST["page"] == "users_registration")
	{
		$firstname = trim(strip_tags($_POST['firstname']));
		$lastname = trim(strip_tags($_POST['lastname']));
		$user_email = trim(strip_tags($_POST['email']));
		$user_password = trim(strip_tags($_POST['passwd']));
		$encrypted_md5_password = md5($user_password);
		
		$check_for_duplicates = mysql_query("select * from `signup_and_login_table` where `email` = '".mysql_real_escape_string($user_email)."'");
		
		if($firstname == "" || $lastname == "" || $user_email == "" || $user_password == "")
		{
			echo '<br><div class="info">กรุณากรอกข้อมูลให้ครบถ้วน</div><br>';
		}
		elseif(!preg_match("/^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,3})$/", $user_email))
		{
			echo '<br><div class="info">กรุณาใส่ E-mail ให้ถูกต้อง</div><br>';
		}
		else if(mysql_num_rows($check_for_duplicates) > 0)
		{
			echo '<br><div class="info">e-mailนี้มันคนใช้แล้ว<br>กรุณาเปลี่ยน e-mailใหม่</div><br>';
		}
		else
		{
			if(mysql_query("insert into `signup_and_login_table` values('', '".mysql_real_escape_string($firstname)."', '".mysql_real_escape_string($lastname)."', '".mysql_real_escape_string($user_email)."', '".mysql_real_escape_string($encrypted_md5_password)."', '".mysql_real_escape_string(date('d-m-Y'))."')"))
			{
				$_SESSION["VALID_USER_ID"] = $user_email;
				$_SESSION["USER_FULLNAME"] = strip_tags($firstname.'&nbsp;'.$lastname);
				echo 'index.php?uid='.$_SESSION["USER_FULLNAME"].'&';
				echo 'registered_successfully=yes';
				
			}
			else
			{
				echo '<br><div class="info">เกิดข้อผิดพลาดไม่สามารถสร้างบัญชีสมาชิกได้ กรุณาลองใหม่อีกครั้ง<br>หรือติดต่อ Admin:[email protected]</br></div><br>';
			}
		}
	}
	//Sign-up Page Ends here
	
	
	//Login Page Starts here
	elseif($_POST["page"] == "users_login") 
	{
		$user_email = trim(strip_tags($_POST['email']));
		$user_password = trim(strip_tags($_POST['passwd']));
		$encrypted_md5_password = md5($user_password);
		
		$validate_user_information = mysql_query("select * from `signup_and_login_table` where `email` = '".mysql_real_escape_string($user_email)."' and `password` = '".mysql_real_escape_string($encrypted_md5_password)."'");
		
		if(mysql_num_rows($validate_user_information) == 1)
		{
			$get_user_information = mysql_fetch_array($validate_user_information);
			$_SESSION["VALID_USER_ID"] = $user_email;
			$_SESSION["USER_FULLNAME"] = strip_tags($get_user_information["firstname"].'&nbsp;'.$get_user_information["lastname"]);
			echo 'index.php?uid='.$_SESSION["USER_FULLNAME"].'&';
			echo 'login_process_completed_successfully=yes';
		}

		else
		{
			echo '<br><div class="info">คุณใส่ รหัสผ่าน หรือ emailผิด กรุณาใส่ให้ถูกต้องด้วยค่ะ</div><br>';
		}
	}
	//Login Page Ends here
}
?>

if(mysql_num_rows($validate_user_information) == 1)
		{
			$get_user_information = mysql_fetch_array($validate_user_information);
			$_SESSION["VALID_USER_ID"] = $user_email;
			$_SESSION["USER_FULLNAME"] = strip_tags($get_user_information["firstname"].' '.$get_user_information["lastname"]);
			echo 'index.php?uid='.$_SESSION["USER_FULLNAME"].'&';
			echo 'login_process_completed_successfully=yes';
		}