relative link for directory above

I've got a file structure like so

Root
-index.html
-adirectory
 ->fileinthedirectory.html

I'd like to create a relati开发者_JAVA百科ve link from fileinthedirectory.html to index.html since /index.html links to /adirectory/index.html which doesn't exist.

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To go up one directory you can use:

 ../index.html

or you can start the URL with a slash to start from the root

 /index.html