drag and drop

<!DOCTYPE html>
<head>
  <meta charset="utf-8">
  <script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.5/d3.min.js"></script>
  <style>
    body { margin:0;position:fixed;top:0;right:0;bottom:0;left:0; }
    svg { width:100%; height: 100% }
  </style>
</head>

<body>
  <script>
    var width = 600, height = 400, circle1;
    var drag = d3.behavior.drag()
    .on('dragstart', dragStart)
    .on('drag', dragElement)
    .on('dragend', dragEnd);
    
    d3.select("#circle1").call(drag);
    
    function dragStart(d, i){}
    
    function dragElement(d, i) {
      circle1.attr("cx", d3.event.sourceEvent.pageX)
      .attr("cy", d3.event.sourceEvent.pageY);
    }
    
    function dragEnd(d, i){}
    
    var svg = d3.select("body")
    .append("svg")
    .attr("width", width)
    .attr("height", height);
    
    circle1 = svg.append("circle")
    .attr("id", "circle1")
    .attr("cx", 50)
    .attr("cy", 50)
    .attr("r", 72)
    .attr("fill", "rgb(69,96,159)")
    .call(drag);
  </script>
</body>

https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.5/d3.min.js