After discovering I could complete my census form online, I was happy for both me (I hate filling out forms) and the people who have to read my scrawl. So I log in and fill out the form and get to about the 2nd last question (think it was the number of bedrooms question) and i mistyped so I used the backspace key 
in an attempt to correct it. Of course this did a page back navigation and effectively locked me out for 1/2 hour. Luck I’m not supposed to fill it out till tonight or I might have given up and just filled out the paper one! Wonder how many people will make the same mistake as me?
