Add login page

login.php

+<?php
+	include('conn.php');
+	session_start();
+	function check_input($data) {
+		$data = trim($data);
+		$data = stripslashes($data);
+		$data = htmlspecialchars($data);
+		return $data;
+	}
+	
+	if ($_SERVER["REQUEST_METHOD"] == "POST") {
+		$username=check_input($_POST['username']);
+		
+		if (!preg_match("/^[a-zA-Z0-9_]*$/",$username)) {
+			$_SESSION['msg'] = "Username should not contain space and special characters!"; 
+			header('location: index.php');
+		}
+		else{
+			
+		$fusername=$username;
+		
+		$password = check_input($_POST["password"]);
+		$fpassword=md5($password);
+		
+		$query=mysqli_query($conn,"select * from `user` where username='$fusername' and password='$fpassword'");
+		
+		if(mysqli_num_rows($query)==0){
+			$_SESSION['msg'] = "Login Failed, Invalid Input!";
+			header('location: index.php');
+		}
+		else{
+			
+			$row=mysqli_fetch_array($query);
+			if ($row['access']==1){
+				$_SESSION['id']=$row['userid'];
+				?>
+				<script>
+					window.alert('Login Success, Welcome Admin!');
+					window.location.href='admin/';
+				</script>
+				<?php
+			}
+			else{
+				$_SESSION['id']=$row['userid'];
+				?>
+				<script>
+					window.alert('Login Success, Welcome User!');
+					window.location.href='user/';
+				</script>
+				<?php
+			}
+		}
+		
+		}
+	}
+?>
\ No newline at end of file