var launchSlideShowX = (screen.width/2)+200;

var launchSlideShowY = (screen.height/2)+200;

var pos = "left="+launchSlideShowX+",top="+launchSlideShowY;

function launchSlideShow(){

launchSlideShowWindow = window.open("picture1.html","SlideShow","width=1000,height=1000,"+pos);}