PHP Code:
<html>
    <h3>Testing Site</h3>
    <form method = "POST" action = "<?php echo $_SERVER['PHP_SELF'];?>">
    <input type = "hidden" name = "send" value = "1">
    <p>UserName<input type = "text" name = "UserName"/></p>
    <p>Password<input type = "text" name = "Password"/></p>
    <input type="submit" value ="Login" />
    </form>
<body background="http://users.pandora.be/creeping_death/Babes/Anna%20Kournikova%2002.jpg">
</body>
<?php
    If($_POST['send']=="1"){
         $filename = "UnP.txt";
         $UserName = $_POST['UserName'];
         $Password = $_POST['Password'];
              $handle = fopen($filename,"r") or die("Err1");
              $contents = @fread($handle,filesize($filename));
              fclose($handle);
                          $Str = strpos($contents,$UserName." ".$Password);
                            If($Str===False){
                              $MakeUser = True;
                            }
                    If($MakeUser = True){
                        $handle = fopen($filename,"w") or die("Err2");
                        $contents = $contents.":$UserName $Password)";
                        fclose($handle);
                        echo "Making Username";
                        }Else{
                            Echo "Logged in!";
                    }
                        }
?>
</html>
Somethings going wrong in these lines:
PHP Code:
                    If($MakeUser = True){
                        $handle = fopen($filename,"w") or die("Err2");
                        $contents = $contents.":$UserName $Password)";
                        fclose($handle);
                        echo "Making Username";
                        }Else{
                            Echo "Logged in!";
                    } 
Because its saying Making Username, but not entering the information (or erroring)..