$(document).ready(function(){
   snow_intensive=400;
   snow_speed=20000;
   snow_src=new Array('/templates/happy2012/images/sneg1.gif','/templates/happy2012/images/sneg2.gif','/templates/happy2012/images/sneg3.gif','/templates/happy2012/images/sneg4.gif');
   snow_start();
});

function snow_start() {
   snow_id=1;
   snow_y=$("#mainblock").height();
   setInterval(function() {
      snow_x=Math.random()*document.body.offsetWidth-100;
      snow_img=(snow_src instanceof Array ? snow_src[Math.floor(Math.random()*snow_src.length)] : snow_src);
      snow_elem='<img class="png" id="snow'+snow_id+'" style="position:absolute; left:'+snow_x+'px; top:0;z-index:10000" src="'+snow_img+'">';
      $("#mainblock").append(snow_elem);
      snow_move(snow_id);
      snow_id++;
   },snow_intensive);
}

function snow_move(id) {
   $('#snow'+id).animate({top:snow_y,left:"+="+Math.random()*100},snow_speed,function() { $(this).empty().remove(); });
}