You should backup your template every time you want to play with the code. Better yet, you always have the latest version of the template that you last change your PC.
Now you have to understand how important it is to have a backup template, let us begin to do:
- Login to your Blogger account (if you are not yet logged in)
- Go to Dashboard, Layout, Edit HTML, click Download Full template and store to your PC, the screen on your PC will look like this :
Under the heading Template Backup / Restore, click the link "Download Full Template" and save the template to your PC and remember where you save the template. It has made you have a backup for your blog template.
If you do not like change, then you can restore the original template by clicking "Browse" and locate the template file you need and click on "Upload" (see picture above), then your template will be restored to the condition you want.