Iwant to validate email in PHP

<?php

session_start();




  if($_POST['name']=="" OR $_POST['name']==""  OR $_POST['number']==""  OR $_POST['nrc']=="" OR $_POST['email']=="" OR $_FILES['upload']['size'] == 0  OR $_POST['password']=="")  {
	  
      $password= md5('$password');
	  
	   $json = json_encode(array(
	   
            'status' => 'notsuccessfull',
            'responseResult' => 'datanotposted'
        ));
	    echo $json;
	    exit;
	  
  
  
  } else {
	    
	 
	 
	 $upload_file = $_FILES['upload'];  
	
	
	//profile
	
	$upload_file_name = $upload_file['name'];
	$upload_file_temp = $upload_file['tmp_name'];
	$upload_file_size = $upload_file['size'];
	$upload_file_error= $upload_file['error'];
 
    // Directory destinations
	
	 $upload_file_destination = '../images/'.$upload_file_name;
	 
	  // Posting to the upload directory
	 
	 if(move_uploaded_file($upload_file_temp ,$upload_file_destination))
		 
	 {
	
          $first=filter_input(INPUT_POST, "name");
		  $last=filter_input(INPUT_POST, "name");
		  $phone=filter_input(INPUT_POST, "number");
		  $identy=filter_input(INPUT_POST, "nrc");
		  $em=filter_input(INPUT_POST, "email");
		  $psw=filter_input(INPUT_POST, "password");
		  
		  $finaluploaddestinate  = '../image/'.$upload_file_name;
		  
		  require_once '../conf/loan.php';

          $conn = new PDO("mysql:host=localhost;dbname=auction", 'root', "");
		
		
		  $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
		  
		  $insertquery = "INSERT INTO signup(first,last,phone,identy,email,pic,pass) VALUES (:f,:l,:p,:i,:e,:pic,:pa)";
		 
		  $insertcustomerinformation = $conn->prepare($insertquery);
			
	      $insertcustomerinformation->bindParam(':f',$first);
		  $insertcustomerinformation->bindParam(':l',$last);
		  $insertcustomerinformation->bindParam(':p',$phone);
		  $insertcustomerinformation->bindParam(':i',$identy);
		  $insertcustomerinformation->bindParam(':e',$em);
		  $insertcustomerinformation->bindParam(':pic',$finaluploaddestinate);
		  $insertcustomerinformation->bindParam(':pa',$psw);
		 
		  $insertcustomerinformation->execute();
							
		  $customerid=$conn->lastInsertId();
		  
		  // End of checking if the business information has been posted to the database
		  
		  if($customerid > 0){
							
				 
				  $json = json_encode(array(
                    'status' => 'successfull',
                    'responseResult' => 'uploadsuccessful'
                  ));

                  echo $json;
							  
				  exit;
							  
							  
							  
			}  else {
							
				  unlink($upload_file_destination);
				 
				  $json = json_encode(array(
	   
                    'status' => 'notsuccessfull',
                    'responseResult' => 'uploadnotsuccessful'
				 
                  ));
		
	             echo $json;
				  
				 exit;
				 
				 
		   }  // End of checking if the business information has been posted to the database
	
			
			 
	 }  else {
		
		// If the posting to the upload has failed do the following
		
		
	}
 
     // End of posting to the upload directory
  
	  
	  
  }
  
  // checking if the image and song file are available
  
	

?>