wx = 580;
wy = 380;
x = (screen.width  - wx) / 2;
y = (screen.height - wy) / 2;

function kiyaku() {window.open("a06_contact2.html","win1","left="+x+",top="+y+",menubar=no,toolbar=no,location=no,directories=no,status=no,scrollbars=yes,width="+wx+",height="+wy);}