set username password

[ashishoc]

is it possible to set username and password for webview using javascript for every login page.
I can able to set username and password if I knew html element id for how can achieve this without knowing elements id cause every login page consist different elements id .please help

          webview.loadUrl("javascript:document.getElementById('email').value = '"+someText+"'; document.getElementById('pass').value = '"+pass+"';  document.getElementById('login_form').submit();  ");