Untitled

<html>


<input type="text" placeholder="username" id="username">
<input type="password" placeholder="password" id="password">

<input type="button" value="Login" id="submit" onclick="validate()"/>
</html>

<script>
var attempt = 3;
function validate(){
var username = document.getElementById("username").value;
var password = document.getElementById("password").value;
if ( username == "username" && password == "password"){
alert ("Login successfully");
window.location = "success.html";
return false;
}
else{
attempt --;//
alert("You have left "+attempt+" attempt;");

if( attempt == 0){
document.getElementById("username").disabled = true;
document.getElementById("password").disabled = true;
document.getElementById("submit").disabled = true;
return false;
}
}
}
</script>