function setPosition(id, position) {
           
            var store = {
                ram : {
                    top : 0,
                    left : 0,
                    right : 0,
                    bottom : 0
                },
                rom : {
                    top : null,
                    left : null,
                    right : null,
                    bottom : null
                }
            };
           
           
            for (var i in position) {store.rom[i] = position[i];}
           
            var element = document.getElementById(id);
           
            for (i in store) {element[i] = store[i];}
           
            element.rom.move = function() {
               
                if (window.innerHeight) {
                    var topPage = window.pageYOffset;
                    var leftPage = window.pageXOffset;
                    var rightPage = leftPage + window.innerWidth - element.offsetWidth;
                    var bottomPage = topPage + window.innerHeight - element.offsetHeight;
                }
                else {
                    var topPage = document.body.scrollTop; 
                    var leftPage = document.body.scrollLeft;
                    var rightPage = leftPage + document.body.clientWidth - element.offsetWidth;
                    var bottomPage = topPage + document.body.clientHeight - element.offsetHeight;
                }
               

                element.style.position = "absolute";
               
                if (element.rom.top != null) {
                    element.ram.top += Math.round((topPage + element.rom.top - element.ram.top)/20);
                    element.style.top = element.ram.top;
                }
                if (element.rom.left != null) {
                    element.ram.left += Math.round((leftPage + element.rom.left - element.ram.left)/20);
                    element.style.left = element.ram.left;
                }
                if (element.rom.right != null) {
                    element.ram.right += Math.round((rightPage - element.rom.right - element.ram.right)/20);
                    element.style.left = element.ram.right;
                }
                if (element.rom.bottom != null) {
                    element.ram.bottom += Math.round((bottomPage - element.rom.bottom - element.ram.bottom)/20);
                    element.style.top = element.ram.bottom;
                }
               
                setTimeout("document.getElementById('"+element.id+"').rom.move()",10);
           
            };   
           
            element.rom.move();
        }
       

        setPosition("a", {top: 20, right: 30});