browser issue for scrolling 50px from top

Question

i need to scroll specific text(say Tooltip1 ) on some event,it has name=tooltip_1. i dont want to scroll it all the way to top but 50 px from top(for better view).

the code below work very fine for safari but is not working for Mozilla and IE.

$("body").animate({scrollTop: $("a[name=tooltip_"+posid_num+"]").offset().top-50},1000);

please let me know if anyone have any suggestion on this.