jQuery.fn.extend({lzqDrag : function(callback,func){
   this.each(function(){
    this.posRange = {minX:0,minY:0,maxX:(document.compatMode == "CSS1Compat"?document.documentElement.clientWidth:document.body.clientWidth),maxY:(document.compatMode == "CSS1Compat"?document.documentElement.clientHeight:document.body.clientHeight)};
    this.onmousedown = function(e){
       this.style.position = "absolute";
       this.drag(e,callback,func);
	   return false;
    }
    this.drag = function(e,callback,func){
        var element = this,ev = e || window.event;
        ev.rScreenX = ev.screenX;
        ev.rScreenY = ev.screenY;
        var pos = $(this).offset();
        element.dragConfig = {defaultX : parseInt(pos.left,10),defaultY : parseInt(pos.top,10),defaultW: parseInt($(this).width(),10),defaultH : parseInt($(this).height(),10)};
        document.onmouseup = function(){element.drop();callback && callback();};
        document.onmousemove = function(e){
            var ev2 = e || window.event;
            if($.browser.msie&& ev2.button!=1){
                return (element.drop(),callback && callback());
            }
            var mx = element.dragConfig.defaultX + (ev2.screenX - ev.rScreenX),
            my = element.dragConfig.defaultY + (ev2.screenY - ev.rScreenY),
            pr = element.posRange,mw = element.dragConfig.defaultW,mh = element.dragConfig.defaultH;
            with(element.style){
                left = (mx<pr.minX?pr.minX:((mx+mw)>pr.maxX?(pr.maxX-mw):mx)) + "px";
                top = (my<pr.minY?pr.minY:((my+mh)>pr.maxY?(pr.maxY-mh):my)) + "px";
            }
            func && func();
            return false;
        };
        document.onselectstart = function(){return false;};
		return false;
    }
    this.drop = function(){document.onmousemove = document.onselectstart = document.onmouseup = null;}})}})