Hello all, ive got the following code to drag and drop an image around the page.

Is there any way of achiving the following
- when the button is clicked, the possition will not be altered. i.e. the position of the image will be saved after the drag and drop has been done.
- not allowing the image to go around the wole of the page, only allow it to drag and drop around say 1/2 of the page

Any ideas?

Code:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">

    protected void Button1_Click(object sender, EventArgs e)
    {

    }
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>Untitled Page</title>
    <style>
<!--
.dragme{position:relative;}
-->
</style>

<script language="JavaScript1.2">
var ie=document.all;
var nn6=document.getElementById&&!document.all;

var isdrag=false;
var x,y;
var dobj;

function movemouse(e)
{
  if (isdrag)
  {
    dobj.style.left = nn6 ? tx + e.clientX - x : tx + event.clientX - x;
    dobj.style.top  = nn6 ? ty + e.clientY - y : ty + event.clientY - y;
    return false;
  }
}

function selectmouse(e) 
{
  var fobj       = nn6 ? e.target : event.srcElement;
  var topelement = nn6 ? "HTML" : "BODY";

  while (fobj.tagName != topelement && fobj.className != "dragme")
  {
    fobj = nn6 ? fobj.parentNode : fobj.parentElement;
  }

  if (fobj.className=="dragme")
  {
    isdrag = true;
    dobj = fobj;
    tx = parseInt(dobj.style.left+0);
    ty = parseInt(dobj.style.top+0);
    x = nn6 ? e.clientX : event.clientX;
    y = nn6 ? e.clientY : event.clientY;
    document.onmousemove=movemouse;
    return false;
  }
}

document.onmousedown=selectmouse;
document.onmouseup=new Function("isdrag=false");
    </script>

</head>
<body>
    <form id="form1" runat="server">
    <div>
        <img src="" class="dragme"/>
        <asp:Button ID="Button1" runat="server" Text="Button" />
    </div>
    </form>
</body>
</html>