Renting Calculation Make Order Name Number of Movies Rented Here is my code, but I'm having trouble adding errors and text alerts. For example I

Make Order

Name
Number of Movies Rented

if(isset($_POST['submit']))

{

$name1=$_POST['userName'];

$price=10.00;

$numberOfMoives=$_POST['numOfMoive'];

if($numberOfMoives<=20)

{

if($numberOfMoives<=2)

$price+=$numberOfMoives*5.50;

else if($numberOfMoives<=4)

{

$price=10.00;

$price+=($numberOfMoives-2)*4.25;

}

else if($numberOfMoives<=7)

{

$price=10.00;

$price+=($numberOfMoives-4)*3.00;

}

else

{

$price=10.00;

$price+=($numberOfMoives-4)*2.00;

}

echo "

".$name1." your total rent is $".number_format($price, 2)."

";

$myfile = fopen("visitor.txt", "w");

fwrite($myfile, $name1);

fclose($myfile);

}

else

{

$message = "you cant not rent more then 20 movies.";

echo "";

}

}

?>

Here is my code, but I'm having trouble adding errors and text alerts. For example I need an error message saying the fields can't be left blank when type in the username and number of movies. Also I need an error message that says you can't type in decimals in the "number of movies" box. Could you please help me?