The decodeURI(...) function has only one variation, not counting syntax variations.  It makes a copy of a String value converting all URI escape sequences to their corresponding character code.  A URI escape sequence consists of the percent sign followed by a two digit hexidecimal value corresponding to the numeric value of a byte. Bytes are converted to characters using a UTF-8 encoding when needed.

Syntax:
decodeURI( source-string )
source-string.decodeURI( )

Parameter	Description
source-string	The String to decode.