slash = "/";
if (operatingsystem == "windows") {slash = "\\";}

if(fileextension(file_to_check) == "fsp") {
    lockfile =  file_to_check+".lock";
    if (!fileexists(lockfile)){
        load(file_to_check);
        status = layoutmode;
        if (status == 1) {
            write(fname,"IF EXIST \""+curdir+slash+lockfile+"\" exit /b 1");
            write(fname,"copy /y NUL "+curdir+slash+lockfile+" >NUL");
            write(fname,"\"C:\Program Files\Lumerical\FDTD\bin\fdtd-engine\" -t 32 "+curdir+slash+files{i});
            write(fname,"echo del "+curdir+slash+lockfile);
            write(fname,"del "+curdir+slash+lockfile);
            write(fname,"exit /b 1");
            if (operatingsystem == "windows") {break;}
            ?"==wrote bat for fsp== "+file_to_check;
        }
    }
}