var mywid = 870;//最初のウインドウの横幅設定　単位ピクセル
var myheight = 870;//最初のウインドウの縦幅設定　単位ピクセル
window.resizeTo(mywid,myheight);

var scr_width = screen.width;
var scr_height = screen.height;
var myPlace_x = (scr_width/2)-(mywid/2);
var myPlace_y = (scr_height/2)-(myheight/2);
window.moveTo(myPlace_x,myPlace_y);