Looks good
, just a few suggestions.
return(""); - all your returns can be in this format: return "";. There is no need for the brackets.
Also it doesn't matter for your script but in programming in general its good to abstract components of your code so you can reuse them. For instance your readclipboard() function reads the data and puts it into the variable ISI. It would be better if instead it just returned the string contents of the clipboard and then in your code you would do something like this:
code:
ISI = readClipboard();
You could do something similiar to the matchISI() function and pass in the ISI variable. It doesn't really have any impact on this script but its just a programming practise that you can use to reuse code
.
Good work!