jQuery(window).scrollTop() issue in Firefox? -

i have following code use display hidden footer when scroll down past point on page.

jquery(document).scroll(function(){     if(jquery(window).scrolltop() >= jquery('.foot').offset().top + jquery('.foot').height() - window.innerheight) {         // add class here     } else {         // remove class here }); 

this works fine in chrome , ie. doesn't work in firefox. i've narrowed problem down jquery(window).scrolltop(). i've created test http://jsfiddle.net/captainmorgan/cvsre/1/ open in chrome , scroll down mouse wheel. 100. when same thing in firefox 114, firefox continues display multiple messageboxes , number keeps decreasing. know why firefox this?

try:

jquery(window).scroll(function(event) {     var nextscroll = jquery(this).scrolltop();     if(nextscroll > (jquery('.foot').offset().top + jquery('.foot').height() - window.innerheight)) {          //action     }  });