Jquery 固定悬浮层以及固定表头

/* ===========================================================
* jquery.autofix_anything.js v1
* ===========================================================
* Copyright 2013 Pete Rojwongsuriya.
* http://www.thepetedesign.com *
* Fix position of anything on your website automatically
* with one js call
*
* https://github.com/peachananr/autofix_anything *
* ========================================================== */

!function($){

var defaults = {
customOffset: false,
manual: false,
onlyInContainer: true
};

$.fn.autofix_anything = function(options){
var settings = $.extend({}, defaults, options),
el = $(this),
curpos = el.position(),
offset = settings.customOffset,
pos = el.offset();

el.addClass("autofix_sb")

$.fn.manualfix = function() {
var el = $(this),
pos = el.offset();
if (el.hasClass("fixed")) {
el.removeClass("fixed")
} else {
el.addClass("fixed").css({
top: 0,
left: pos.left,
right: "auto",
bottom: "auto"
});
}

}

fixAll = function(el, settings, curpos, pos){
if (settings.customOffset == false) offset =  el.parent().offset().top
if($(document).scrollTop() > offset && $(document).scrollTop() <= (el.parent().height() + (offset - $(window).height())))  {
el.removeClass("bottom").addClass("fixed").css({
top: 0,
left: pos.left,
right: "auto",
bottom: "auto"
});
} else {
if($(document).scrollTop() > offset) {
if (settings.onlyInContainer == true ) {
if($(document).scrollTop() > (el.parent().height() - $(window).height())) {
el.addClass("bottom fixed").removeAttr( 'style' ).css({
left: curpos.left
});
}else {
el.removeClass("bottom fixed").removeAttr( 'style' );

}
}
} else {
el.removeClass("bottom fixed").removeAttr( 'style' );
}
}

}
if (settings.manual == false) {
$(window).scroll(function() {
fixAll(el, settings, curpos, pos)
});
}

}
}(window.jQuery);

.autofix_sb.fixed {
position: fixed !important;
left: auto;
top: auto;
right: auto;
bottom: auto;
height: 100%;
overflow:auto;

<script type="text/javascript">
$(document).ready( function() {
$(".sidebar").autofix_anything();
});

</script>

} .autofix_sb.fixed.bottom { bottom: 0; position: absolute !important; }