Well, I hadnt given it enough thought ... this should work though:
var myDoc = app.activeDocument;
// define the variables
var myDoc = app.activeDocument;
var x2 = (myDoc.width);
var y2 = (myDoc.height);
// for landscape
if (x2 > y2) {
if (x2/y2 > 1.5) {
myDoc.resizeCanvas (x2, x2/1.5, AnchorPosition.MIDDLECENTER)
}
if (x2/y2 < 1.5) {
myDoc.resizeCanvas (y2*1.5, y2, AnchorPosition.MIDDLECENTER)
}
}
// for portrait
if (x2 < y2) {
if (y2/x2 > 1.5) {
myDoc.resizeCanvas (y2/1.5, y2, AnchorPosition.MIDDLECENTER)
}
if (y2/x2 < 1.5) {
myDoc.resizeCanvas (x2, x2*1.5, AnchorPosition.MIDDLECENTER)
}
}