Version history

Version 1.0
Function Added
   Version 1.1
typo fix
   Version 1.2
   Version 1.3
Fixed a bug when the string is not found and the occurrence is greater than 1
   Version 1.4
fixed a (big) bug and a spelling error in a parameter name
   Version 1.5
changed variables names
   Version 1.6
Returns empty if the search string is not found. Does not use local variables anymore. More readable
   Version 1.7