[ruslan_mart]

<div onmouserdown="drag(event, this)" style="background:red; height:100px; width:100px"></div>

function drag(a, b)
{
   a = a || window.event;
   b.clicked = true;
   b.mousePosX = a.clientX;
   b.mousePosY = a.clientY;
   if(a.preventDefault) a.preventDefault(); 
   else a.returnValue = false;
   document.onmouseup = function()
   {
      b.clicked = false;
   }
   document.onmousemove = function(a)
   {
      a = a || window.event;
      if(b.clicked)
      {
         posLeft = !b.style.marginLeft ? b.offsetLeft : parseInt(b.style.marginLeft);
         posTop = !b.style.marginTop ? b.offsetTop : parseInt(b.style.marginTop);
         mousePosX = a.clientX;
         mousePosY = a.clientY;
         b.style.marginLeft = posLeft + mousePosX - b.mousePosX + 'px';
         b.style.marginTop = posTop + mousePosY - b.mousePosY + 'px';
         b.mousePosX = mousePosX;
         b.mousePosY = mousePosY;
      }
   }
}