I found that any text field above a password field has a default value of “Password”, and there is a default password value also.
That’s a ‘feature’ of the browser you are using. It will go away if you clear your browser cache, cookies etc.
right! thank you
For your interest, is is the form autocompletion feature of browsers. Now we know you have a user “Password” with password “********” somewhere. 
if the browser was showing one of my account name, I would know it’s browser autosave function and I wouldn’t post my question here…
it was strange that if i switch the position of the 2 fields, the problem won’t appear. but anyways, it works now.