'undefined' is not an object (evaluating 'field.getAttribute')

Question

i have used code from link below to login.. it works fine with facebook .. How to login into a website with CasperJS?

but it give error for login page of my site. name of username field is LoginForm[username] and name of password field is LoginForm[password].

My code.

casper.start(url, function() {
   // search for 'casperjs' from google form
   console.log("page loaded");
   this.test.assertExists('form#login-form', 'form is found');     
   this.fill('form#login-form', { 
        LoginForm[username]: 'ascd@csc.com', 
        LoginForm[password]: '******'
    }, true);
});

output

[info] [remote] attempting to fetch form element from selector: 'form#login-form'
remote message caught: attempting to fetch form element from selector: 'form#login-form'
[error] [remote] TypeError: 'undefined' is not an object (evaluating 'field.getAttribute')
remote message caught: TypeError: 'undefined' is not an object (evaluating 'field.getAttribute')
Page Error: TypeError: 'undefined' is not an object (evaluating 'field.getAttribute')
FAIL CasperError: Unable to fill form
#    type: uncaughtError
#    error: "CasperError: Unable to fill form"
CasperError: Unable to fill form

//// HTML

Answer 1

this.fill('form#login-form', { 
    'LoginForm[username]': 'ascd@csc.com', 
    'LoginForm[password]': '******'
}, true);