Using "FInd" as the name may be the problem.
System or Application reserved names can sometimes cause problems.
Not tested, just a suggestion.
"Find" is sample.
Real name is different and korean.
thus i think system don't confuse.
I don't see anything obviously wrong with your script.
when i try, it do not work.
How does it not work? (what do you see on the screen?)
If you want to look at a file where this method is used, you could down load this file:
The Find button in this file pops up such a window, but uses global fields to collect the search criteria. The method for opening a separate window should be much the same, however.