I don't know why my spreadsheet has suddenly gone mad, but it has locked up and won't move.A little square note appeared in the bottom corner saying something about the browser or something being frozen. I know nothing about computers, I've been trying for the last hour to make the spreadsheet bigger (it has become smaller and the little thing at the side that the mouse clicks on to go up and down has disappeared) and gave up. I'm scared to press too many buttons in case I delete any data. Also, last night one of my cats sat on the keys while I left it unattended for about ten minutes and managed to delete all the columns from October to the end of the year. Can't remember too well because I can't get into it to check. Don't know how to get that back either! Haven't got a clue what to do and just hope that it can be fixed?! I don't think that the cat has done all the damage because today I've managed to put data in before it all went haywire. Would be very grateful for any advice.