$(document).ready(function(){
    var defaultUsername = "username";
    var defaultPassword = "password";

    $("#username").focus(function() {
        var tmp = $(this).val();
        //set window location
        if (tmp == defaultUsername) {
            $(this).val("");
        }
    });
    $("#password").focus(function() {
        var tmp = $(this).val();
        //set window location
        if (tmp == defaultPassword) {
            $(this).val("");
        }
    });
    $("#username").val("username");
    $("#password").val("password");
});