If, when you put your username & password in the blank spaces, and click "Login"... the screen just blinks & empties your entries... there is either a problem with the way your machine is handling "cookies" or your Cache is becoming clogged.  It's easy to fix!

Assuming you are using Internet Explorer...at the top of your screen, click on "Tools", then "Internet Options", then under the "Temporary Internet" heading... first...click on "Delete Cookies", then click on "Delete Files".  When it's through, click OK.  This should clear your Cache out & you should be able to log-in without a problem (of course you must be using the correct username & password.)

Best regards,
Dave