how to save as pdf form using script ?

i'm using adobe acrobat XI
i want to make a button that can save as the pdf file to local disk such as "D:/test/testing.pdf"

i want to do it using a script

i already look at this website : https://acrobatusers.com/tutorials/how-save-pdf-acrobat-javascript

but my button did not work, i don't know why

the code i'm using are :

this.saveAs("/d/test/testing.pdf");

and

this.saveAs("/d/test/" + this.documentFileName);

and this one got an error message when i use it

// Split Path into an array so it is easy to work with

var aMyPath = this.path.split("/);

// Remove old file name

aMyPath.pop();

// Add new file name

aMyPath.push("NewFileName.pdf");

// Put path back together and save

this.saveAs(aMyPath.join("/"));

i hope a response for this question

thanks for all your help