拖动效果

css部分：

<style type="text/css">.page{text-align:left;}.dragDiv{
　　 border:1px solid #ddd;
 　　padding:10px;
 　　width:300px;
 　　height:150px;
　　 margin:0 auto;
 　　border-radius:4px; 
　　 box-shadow:0 1px 2px #fefefe; 
　　 position: fixed;
    }
</style>

html部分：

<div class="dragDiv" id="drag"><div class="drag-head"></div><div class="drag-body">drag me</div>
</div>

js部分：（此处需要引入jquery.js）

<script>var _drag = {};_drag.top = 0; //拖动过的位置距离上边
    _drag.left = 0; //拖动过的位置距离左边
    _drag.maxLeft; //距离左边最大的距离
    _drag.maxTop; //距离上边最大的距离
    _drag.dragging = false; //是否拖动标志//拖动函数function bindDrag(el){var winWidth = $(window).width(), winHeight =$(window).height(),objWidth = $(el).outerWidth(), objHeight = $(el).outerHeight();_drag.maxLeft = winWidth - objWidth, _drag.maxTop = winHeight - objHeight;var els = el.style,x=0,y=0;var objTop = $(el).offset().top, objLeft = $(el).offset().left;$(el).mousedown(function(e){_drag.dragging = true;_drag.isDragged = true;x = e.clientX - el.offsetLeft;y = e.clientY - el.offsetTop;el.setCapture && el.setCapture();$(document).bind('mousemove',mouseMove).bind('mouseup',mouseUp);return false;});function mouseMove(e){e = e || window.event;if(_drag.dragging){_drag.top = e.clientY - y;_drag.left = e.clientX - x;_drag.top = _drag.top > _drag.maxTop ? _drag.maxTop : _drag.top;_drag.left = _drag.left > _drag.maxLeft ? _drag.maxLeft : _drag.left;_drag.top = _drag.top < 0 ? 0 : _drag.top;_drag.left = _drag.left <0 ? 0 : _drag.left;els.top = _drag.top + 'px';els.left = _drag.left+ 'px';return false;}}function mouseUp(e){_drag.dragging = false;el.releaseCapture && el.releaseCapture();e.cancelBubble = true;$(document).unbind('mousemove',mouseMove).unbind('mouseup',mouseUp);}$(window).resize(function(){var winWidth = $(window).width(),winHeight = $(window).height(),el = $(el),elWidth = el.outerWidth(),elHeight = el.outerHeight(),elLeft = parseFloat(el.css('left')),elTop = parseFloat(el.css('top'));_drag.maxLeft = winWidth - elWidth;_drag.maxTop = winHeight - elHeight;_drag.top = _drag.maxTop < elTop ? _drag.maxTop : elTop;_drag.left = _drag.maxLeft < elLeft ? _drag.maxLeft : elLeft;el.css({top:_drag.top,left:_drag.left})})}bindDrag(document.getElementById('drag'));
</script>