全アートボード版
if ( documents.length > 0){

var d = activeDocument;
var abs = d.artboards;
var dv = d.views[0];

var a = abs[0].artboardRect;
for(var i=abs.length; i--;) {
a = maxRect(a, abs[i].artboardRect);
}

dv.zoom = 1;
dv.centerPoint = [(a[0]+a[2]) / 2, (a[1]+a[3]) / 2];
var v = dv.bounds;

dv.zoom = Math.min((v[2]-v[0]) / (a[2]-a[0]), (v[1]-v[3]) / (a[1]-a[3])) * 0.85;
}

function maxRect(a, b)
{
return [Math.min(a[0], b[0]),Math.max(a[1], b[1]),Math.max(a[2], b[2]),Math.min(a[3], b[3])];
}