js源码--简单的div拖动

< html >
< head >

< meta http - equiv = " Content-Type "  content = " text/html; charset=gb2312 " ></ head >
< BODY style = " margin:0;padding:0; " >  
< div id = " dMsgBody "  style = " border:1px solid;position:absolute  " >
< div id = " dTitle "  style = " background-color:#CCCCCC  " > 这是标题，拖动这里可以实现拖动效果 </ div >
< div id = " dTxtBody " > 这是正文，拖动这里不可以实现拖协效果 </ div >
</ div >
</ body >
< script language = " javascript " >
var  object ;
window.onload  =  startUp(document.getElementById( " dMsgBody " ));
function startUp(obj)...... ... {
obj.onmousemove  =  mousemove;
obj.onmousedown  =  mousedown;
obj.onmouseup  =  mouseup;
}

function mousemove()...... ... {
if ( object != null )...... ... {
object .style.pixelTop  =   event .clientY  - object.objY;
object .style.pixelLeft  =   event .clientX  - object.objX;
}
}

function mousedown( event ,obj)...... ... {
obj = obj || this ;
event = event || window. event ;
obj.setCapture();
object = obj;
// objX = event.offsetX;
// objY = event.offsetY;
obj. objX  =   event .clientX - obj.style.pixelLeft;
obj. objY  =   event .clientY - obj.style.pixelTop;
// alert(obj.offsetTop+"   "+obj.style.pixelTop) offset是和body标签的距离，所以会有空隙才能等效，所以在body上加了css
}

function mouseup()...... ... {
if ( object != null )...... ... {
     object .releaseCapture();
     object = null   
}
}
</ script >
</ html >  

自己写了个，这个应该是比较简单通用的