<div id="snake"></div>
<input type="button" value="start" id="bt1" >
<script>
$("#bt1").click(function(){
$(document).bind('keydown', function(e) {
var head = $("#snake"),
left = 37,
up = 38,
right = 39,
down = 40
switch(e.keyCode){
case left:
head.animate({"left":"-=10"},"200");
break;
case up:
head.animate({"top":"-=10"},200);
break;
case right:
head.animate({"left":"+=10"},200);
break;
case down:
head.animate({"top":"+=10"},200);
break;
}
});
});
</script>