function ContactUsForm()
{
    this.form = new Form(this.getIds());
}

ContactUsForm.prototype.submitForm = function()
{
    if (this.isAValidForm())
    {
        document.getElementById('source').value = 'Contact Us';
        return true;
    }
    else
    {
        return false;
    }
}

ContactUsForm.prototype.isAValidForm = function()
{
    var isValid = this.form.isAValidForm();
    
    if (!this.form.isAValidInput('your_message'))
    {
        isValid = false;
    }
    
    return isValid;
}

ContactUsForm.prototype.getIds = function()
{
    return new Array('first_name', 'last_name', 'email', 'confirm_email', 'your_message');
}