// calculation
if (scalable) {
  layout[W] = Math.round(BWidth - 0.02 * layoutborderclear * BWidth);
  if (layout[W] > layoutwidthmax) layout[W] = layoutwidthmax;
  if (layout[W] < layoutwidthmin) layout[W] = layoutwidthmin;
}
else layout[W] = layoutwidthmax;
var scale = layout[W] / layoutwidthmax;
layout[H] = Math.round(layout[W] * layoutratio);
layout[X] = Math.round(BCenter[X] - layout[W] / 2);
if (layout[X] < 0) layout[X] = 0;
layout[Y] = Math.round(BCenter[Y] - layout[H] / 2);
if (layout[Y] < 0) layout[Y] = 0;

// set layout
setstyle('layout', [
  ['backgroundColor', colorpetrol],
  ['left', layout[X]],
  ['top', layout[Y]],
  ['width', layout[W]],
  ['height', layout[H]]
]);