You would need to use the below script excerpt to grab the text across the screen.. You will also need to use the screen with the On Screen Update.. this does not come with out its faults as it will log each keypress and then the final log in
Text = Get_Screen_Text_Columns( ROW, COLUMN, HOW MANY COLUMNS TO COUNT OVER TO )
Text = Get_Screen_Text_Columns( 6, 53, 5 )
Instead of using the "On Screen Update" activation method it would be more efficient to utilize the Screen Reformatter for identifying your Log in screen and then call a supporting action script through the reformatter.
What Matt said.. If you are familiar with the reformatter that would be the way to go as "On Screen Update" runs the script with every action performed, this would include key presses..