Opposite of "scrollTop" in jQuery -

jquery has function called scrolltop can used find number of pixels hidden above current page view.

i'm not sure why, there no scrollbottom function returns number of pixels below current page view.

is there jquery plugin adds functionality? or going require elaborate math window/document height , scrolltop value?

you make pretty simple plugin this:

$.fn.scrollbottom = function() {    return $(document).height() - this.scrolltop() - this.height();  }; 

then call on whatever element wanted, example:

$(window).scrollbottom();  //how many pixels below current view $("#elem").scrollbottom(); //how many pixels below element