fixed validate code.php

<?php


function security($data){
	$data=trim($data);
	$data=stripcslashes($data);
	$data=htmlentities($data);
	return $data;
}	
$output="";
function insert(){
	
	global $output;
	 
	global $connection;
	$name =$lastname = "";
	$name=security($_POST["name"]);
	$lastname=security($_POST["lastname"]);
	$query= " INSERT INTO m1 (";
	$query .= "  name, lastname";
	$query .= ") VALUES (";
	$query .= " '{$name}', '{$lastname}' ";
	$query .= ")";
	
	if($_SERVER["REQUEST_METHOD"]=="POST"){
	
		if(empty($name) || empty($lastname)){
				$output .= "feids is not empty.<br>";
		}else{
				if(mysqli_query($connection,$query)){
					$output .= "success";
					
				}
				else{
					$output .= "failds..";
				}
			}
	
	}
	return $output;
}	
	
?>

validation.php

<?php

function security($data){
	$data=trim($data);
	$data=stripcslashes($data);
	$data=htmlentities($data);
	return $data;
}	
function insert(){
	global $output;
	global $result;
	global $connection;
	$name =$lastname = "";
	$name=security($_POST["name"]);
	$lastname=security($_POST["lastname"]);
	$query= " INSERT INTO m1 (";
	$query .= " name, lastname";
	$query .= ") VALUES (";
	$query .= " '{$name}', '{$lastname}' ";
	$query .= ")";
	$result=mysqli_query($connection,$query);
	if($_POST['submit']){
	
		if(empty($name) || empty($lastname)){
				$output = "feids is not empty.<br>";
		}else{
				if(isset($result)){
					$output .= "success";
				}
				else{
					$output .= "failds..";
				}
			}
	return $output;
	}
}	
	
?>