アイコン拡大
var ar = new Array(16,32,48,96,128,192,256);
var FV = GetFolderView(Ctrl, pt);
for(var i = 0; i < ar.length; i++) {if ( FV.IconSize < ar[i]) {FV.IconSize(ar[i]);break;}}

アイコン縮小
var ar = new Array(16,32,48,96,128,192,256);
var FV = GetFolderView(Ctrl, pt);
for(var i = ar.length-1; i >= 0; i--) {if ( FV.IconSize > ar[i]) {FV.IconSize(ar[i]);break;}}