Browser Control not waiting for page to fully load C#

Question

I'm having issues with a browser control in a windows form. I've searched for waiting for a page to fully load, but it seems to want to fire off before the page loads anyway. Here is the code:

    private void loginToML()
    {

        string userName = Globals.SCMAddin.getUserName();
        string userPassword = Globals.SCMAddin.getUserPassword();

        try
        {
            HtmlDocument doc = browser_Window.Document;
            doc.GetElementById("ctl00_ctl00_cphNestedUtility_cphLeft1_ctlValidateUser_ctl00_txtUserid").SetAttribute("value", userName);
            doc.GetElementById("ctl00_ctl00_cphNestedUtility_cphLeft1_ctlValidateUser_ctl00_btnValidate").InvokeMember("click");

            waitforIE();

            doc = browser_Window.Document;
            doc.GetElementById("ctl00_ctl00_cphNestedUtility_cphLeftContent_ctlValidateUser_ctl00_txtPassword").SetAttribute("value", userPassword);
            doc.GetElementById("ctl00_ctl00_cphNestedUtility_cphLeftContent_ctlValidateUser_ctl00_btnContinue").InvokeMember("click");

            waitforIE();

            this.loggedIn = true;

        }
        catch (Exception loginError)
        {
            throw new Exception("Error Logging In");
        }

    }//END LOGINTOML

    private void waitforIE()
    {
        while (browser_Window.ReadyState != WebBrowserReadyState.Complete)
        {
            Application.DoEvents();
        }
    }//END WAITFORIE

The website to login to is https://olui2.fs.ml.com/login/login.aspx

I had this working in Excel VBA, but I've been transferring most of my code over to an Excel Add-In.