JAVASCRIPT

password page javascript

var passwordText = document.getElementById("id").value;
if(passwordText == "hello300") {
  return true;
}
else {
  alert("Not correct")
  return false
}

show password using javascript

<script>
$(document).ready(function(){
    $('#checkbox').on('change', function(){
        $('#password').attr('type',$('#checkbox').prop('checked')==true?"text":"password"); 
    });
});
</script>
<input type="password" id="password"> 
<input type="checkbox" id="checkbox">Show Password