ปัญหาทำให้เว็บโหลดช้ามาก ต้องเปลี่ยนไปใช้ยังไงดีคะ (การเรียกไฟล์)

 <?
 	$pagename=$_GET['pagename'];	
 	
 	if($pagename=="login"){
		include("member/login-register.php");
		}else if ($pagename=="pro_contruction"){
			include("products/pro_contruction.php");
		}else if ($pagename=="pro_ceramic"){
			include("products/pro_ceramic.php");
		}else if ($pagename=="pro_electrical"){
			include("products/pro_electrical.php");
		}else if ($pagename=="pro_feruiture"){
			include("products/pro_feruiture.php");
		}else if ($pagename=="pro_door"){
			include("products/pro_door.php");	
		}else if ($pagename=="pro_kitchen"){
			include("products/pro_kitchen.php");
		}else if ($pagename=="member"){
			include("member/member.php");	
		}else if ($pagename=="checkuser"){
			include("member/checkuser.php");	
		}else if ($pagename=="editprofile"){
			include("member/edit_profile_form.php");
		}else if ($pagename=="checkpoint"){
			include("member/checkpoint.php");
		}else if ($pagename=="prostore"){
			include("promotion/view_pro_store.php");	
		}else if ($pagename=="aboutus"){
			include("aboutus.php");		
		}else if ($pagename=="contact"){
			include("contact/contact.php");
		}else if ($pagename=="career"){
			include("career/career.php");	
		}else if ($pagename=="application"){
			include("career/application.php");																	
		 }else{

<ul>
        <li><a href="index.php">Home</a></li>
            <li><a href="index.php?pagename=aboutus">About Us</a></li>
            <li><a href="index.php?pagename=contact">Contact Us</a></li>
            <li><a href="index.php?pagename=login">Register / Login</a></li>
        </ul>