<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Validation - JavaScript Introduction</title>
</head>
<body>
<form>
<input type="text" id="uname" name="uname" placeholder="Your name min 5 char..." />
<button type="button"
onclick="if(document.getElementById('uname').value.length < 5){
document.getElementById('uname').style.border = '1px solid #FF0000';
alert('Enter at least 5 character!');
} else {
document.getElementById('uname').style.border = '1px solid #41B353';
alert('You entered more then 5 character!');
}">Submit</button>
</form>
</body>
</html>
