Repeat for each artboard problem

Question

I have a script that make makes guides around the edge of the artboard. It works fine when you only have one artboard but has issues when there are more. Can anyone see what's wrong here?
#target illustrator
var docRef = app.activeDocument;
var artboardRef = docRef.artboards;
//repeat for each artboard
for(i=0;i<artboardRef.length;i++){
  //get artboard size
  var left=artboardRef[i].artboardRect[0];
  var top=artboardRef[i].artboardRect[1] ;
  var right=artboardRef[i].artboardRect[2] ;
  var bottom=artboardRef[i].artboardRect[3] ;
  //create lines
  var lineLeft = docRef.pathItems.add();
  var lineRight = docRef.pathItems.add();
  var lineTop = docRef.pathItems.add();
  var lineBottom = docRef.pathItems.add();
  //set line points
  var leftmargin = (72);
  var rightmargin = (72);
  var topmargin = (72);
  var bottommargin = (72);
  //set line points
  lineLeft.setEntirePath([[leftmargin, 0], [leftmargin, bottom]]);
  lineRight.setEntirePath([[right - rightmargin, 0], [right - rightmargin, bottom]]);
  lineTop.setEntirePath([[0, 0 - topmargin], [right, 0 - topmargin]]);
  lineBottom.setEntirePath([[0, bottom + bottommargin], [right, bottom + bottommargin]]);
  //make lines guides
  lineLeft.guides = true;
  lineRight.guides = true;
  lineTop.guides = true;
  lineBottom.guides = true;

Answer 1

you have hard coded "0", it needs to be changed to variables, otherwise it will point to the same x or y coordinates
//set line points
  lineLeft.setEntirePath([[left+leftmargin, top], [left+leftmargin, bottom]]);
  lineRight.setEntirePath([[right - rightmargin, top], [right - rightmargin, bottom]]);
  lineTop.setEntirePath([[left, top - topmargin], [right, top - topmargin]]);
  lineBottom.setEntirePath([[left, bottom + bottommargin], [right, bottom + bottommargin]]);