PHP login form issue with coding -

notice: undefined index: myusername in c:\xampp\htdocs\login_in2.php on line 14 wrong username or password

<?php  $host="localhost"; // host name  $username="root"; // mysql username  $password=""; // mysql password  $db_name="test"; // database name  $tbl_name="members"; // table name   // connect server , select databse. mysql_connect("$host", "$username", "$password")or die("cannot connect");  mysql_select_db("$db_name")or die("cannot select db");  // username , password sent form  $myusername=$_post['myusername'];  $mypassword=$_post['mypassword'];   // protect mysql injection (more detail mysql injection) $myusername = stripslashes($myusername); $mypassword = stripslashes($mypassword); $myusername = mysql_real_escape_string($myusername); $mypassword = mysql_real_escape_string($mypassword); $sql="select * $tbl_name username='$myusername' , password='$mypassword'"; $result=mysql_query($sql);  // mysql_num_row counting table row $count=mysql_num_rows($result);  // if result matched $myusername , $mypassword, table row must 1 row if($count==1){  // register $myusername, $mypassword , redirect file "login_success.php"  header("location:login_success.php"); } else { echo "wrong username or password"; } ?> 

the data not being submitted, error related trying access variable @ $_post[''].

some simple error checking should fix it:

<?php  [..]  if ( isset( $_post['myusername'] ) && isset( $_post['mypassword'] ) ) {  // username , password sent form  $myusername=$_post['myusername'];  $mypassword=$_post['mypassword'];   [...]  } ?>