Javascript Native Drag

drag.html

<div id="one">
</div>

drag.js

window.onload = function(){

    draggable('one');

};

var dragObj = null;
function draggable(id)
{
    var obj = document.getElementById(id);
    obj.style.position = "absolute";
    obj.onmousedown = function(){
            dragObj = obj;
    }
}
 
document.onmouseup = function(e){
    dragObj = null;
};

document.onmousemove = function(e){
    var x = e.pageX;
    var y = e.pageY;

    if(dragObj == null)
        return;

    dragObj.style.left = x +"px";
    dragObj.style.top= y +"px";
};