Commander X16

I want to make a very simple like a disk util or file manager in basic for the commander but how do open a file and delete it with the file name that the user typed in I know you can delete files with open15,8,15,"s:filename":close1

10 PRINT "FILENAME";
20 INPUT A$
30 DOS "S:"+A$

Thanks, I kinda figured it was that oof do I feel silly