{
var step = 1;               // How many pixels to move per step
var current = 0;            // The current pixel row
var restartPosition = 1689;	//The pixel row where to start a new loop

function scrollBg(){
    current -= step;
    if (current == restartPosition){
        current = 0;
    }
    $('#screenshots').css("background-position","center "+current+"px");
}
var init = setInterval("scrollBg()", 25);
}