How to determine if a PDF with the same name at the current location is open?

I export a PDF using the following statement, but sometimes there are exceptions. Later, I found out that a PDF with the same location and name is open.

Like this:

var myPDFFile = new File(desktopPath + "/" + exPDFname + "/" + getpRange + ".pdf");
    //if (myPDFFile.isOpen) {
    //    alert('Please close the PDF with the same name first');
    //}
myDocument.exportFile(ExportFormat.PDF_TYPE, myPDFFile, false, preSle);

Or more scientifically:
Automatically close the 'myPDFFile' currently open in Acrobat.