Login Problem

$Logon_Username = mysqli_real_escape_string($connect, $_POST['Username']);
  $Logon_Password = mysqli_real_escape_string($connect, $_POST['Password']);
  $Logon_Button = mysqli_real_escape_string($connect, $_POST['Logon_button']);


  $Logon_Message = "";


  if(!isset($Logon_Button)){


  }else{
   if(empty($Logon_Username) || empty($Logon_Password)){
        	$Logon_Message = '
             <div class="alert alert-danger alert-danger" role="alert">
              <button type="button" class="close" data-dismiss="alert" aria-label="Close"><span aria-hidden="true">&times;</span></button>
              <strong>Achtung!</strong> Bitte fülle alle Felder aus!
             </div>
        	';
   }else{
   	 $UsernameSelect = mysqli_query($ConnectMe, "SELECT Username,Password FROM User WHERE Username = '$Logon_Username' LIMIT 1");
     $UsernameCount = mysqli_num_rows($UsernameSelect);


     if($UsernameCount == 1){
     	$Logon_Password = strtoupper(md5($Logon_Password));


     	$PasswordFetch = mysqli_fetch_object($UsernameSelect);
     	$Password2 = $PasswordFetch->Password;


     	if($Logon_Password == $Password2){
     		$_SESSION['UserCookie'] = $Logon_Username;
     		header(''.$WEBSITE.'Channel/?i='.$MyChannelHash.'');
     	}else{
     		$Logon_Message = '
             <div class="alert alert-danger alert-danger" role="alert">
              <button type="button" class="close" data-dismiss="alert" aria-label="Close"><span aria-hidden="true">&times;</span></button>
              <strong>Achtung!</strong> Passwort ist falsch!
             </div>
        	';
     	}
     }else{
     	    $Logon_Message = '
             <div class="alert alert-danger alert-danger" role="alert">
              <button type="button" class="close" data-dismiss="alert" aria-label="Close"><span aria-hidden="true">&times;</span></button>
              <strong>Achtung!</strong> Dieser User existiert nicht!
             </div>
        	';
     }
   }
  }