js special effects, small example of snow on the page_javascript skills

if (arr[i]){
var ofs=$ (this).offset();
var x=parseInt(ofs.left);
var y =parseInt(ofs.top);
var vy=parseInt($(this).attr(" vy"));
x =wind;
vy *= ay;
y = vy;
$(this).offset({"top":y}) ;
                 $ (this).offset({"left":x});
                                                                                                                                                                                                                  


This is its core code, there is nothing mysterious about it. I won’t explain it more. BYE.