I think I got it. I changed the username fields as Sunfighter suggested and the while process works.
However, the whiole idea of changing to this method was to get the text labels on top of the box fields. Before I porsted I had managed that but the page was not working. Now it is working by«ut the two boxes that were side by side are now on different levels...
I've only changed userbame and password. the ones below are still as they were in the previous stage.
Can you see why the fields have moved, please?
This is the appropriate code in the css file
background: #BABD98; /*demo only*/