基于jquery的jqDnR拖拽溢出的修改

/* 
* jqDnR - Minimalistic Drag'n'Resize for jQuery. 
* 
* Copyright (c) 2007 Brice Burgess <[e-mail]>, http://www.iceburg.net/ 
* Licensed under the MIT License: 
* http://www.opensource.org/licenses/mit-license.php 
* 
* $Version: 2007.08.19 +r2 
* last modified by leegle 2011.02.11 
* fix bug:溢出之后不能回来的,添加在范围内移动 
*/ 
(function($) { 
$.fn.jqDrag = function(h) { return i(this, h, 'd'); }; 
$.fn.jqResize = function(h) { return i(this, h, 'r'); }; 
$.jqDnR = { dnr: {}, e: 0, 
drag: function(v) { 
if (M.k == 'd') { 
//修改的位置 李飞二?一一年二月十一日 14:35:19 
E.css({ left: (M.X + v.pageX - M.pX)<0? 0:(M.X + v.pageX - M.pX)<document.documentElement.clientWidth- M.W?(M.X + v.pageX - M.pX):document.documentElement.clientWidth- M.W, top: (M.Y + v.pageY - M.pY)<0?0:(M.Y + v.pageY - M.pY)<document.documentElement.clientHeight -M.H ?(M.Y + v.pageY - M.pY): document.documentElement.clientHeight- M.H }); 
} 
else {E.css({ width: Math.max(v.pageX - M.pX + M.W, 0), height: Math.max(v.pageY - M.pY + M.H, 0) }); return false;} 
}, 
stop: function() { E.css('opacity', M.o); $(document).unbind('mousemove', J.drag).unbind('mouseup', J.stop); } 
}; 
var J = $.jqDnR, M = J.dnr, E = J.e, 
i = function(e, h, k) { 
return e.each(function() { 
h = (h) ? $(h, e) : e; 
h.bind('mousedown', { e: e, k: k }, function(v) { 
var d = v.data, p = {}; E = d.e; 
// attempt utilization of dimensions plugin to fix IE issues 
if (E.css('position') != 'relative') { 
p = E.position(); 
if (!($.browser.msie && ($.browser.version == "6.0")) && (E.css('position') == 'fixed')) { 
p.top -= $(window).scrollTop(); p.left -= $(window).scrollLeft() 
} 
} 
M = { X: p.left || f('left') || 0, Y: p.top || f('top') || 0, W: f('width') || E[0].scrollWidth || 0, H: f('height') || E[0].scrollHeight || 0, pX: v.pageX, pY: v.pageY, k: d.k, o: E.css('opacity') }; 
E.css({ opacity: 0.8 }); $(document).mousemove($.jqDnR.drag).mouseup($.jqDnR.stop); 
return false; 
}); 
}); 
}, 
f = function(k) { return parseInt(E.css(k)) || false; }; 
})(jQuery);