var xPos = 20;
var yPos = document.body.clientHeight;
var floatStep = 1;
var floatDelay = 30; 
var height = 0;
var Hoffset = 0;
var Woffset = 0;
var yon = 0;
var xon = 0;
var floatHandle;
var FOBJ=null;
function changePos() {
    width = document.body.clientWidth;
    height = document.body.clientHeight;
    Hoffset = FOBJ.offsetHeight;
    Woffset = FOBJ.offsetWidth;
    FOBJ.style.left = xPos + document.body.scrollLeft;
    FOBJ.style.top = yPos + document.body.scrollTop;
    if (yon) yPos = yPos + floatStep;
    else yPos = yPos - floatStep;

    if (yPos < 0) {
        yon = 1;
        yPos = 0;
    }
    if (yPos >= (height - Hoffset)) {
        yon = 0;
        yPos = (height - Hoffset);
    }
    if (xon) {
        xPos = xPos + floatStep;
    }
    else {
        xPos = xPos - floatStep;
    }
    if (xPos < 0) {
        xon = 1;
        xPos = 0;
    }
    if (xPos >= (width - Woffset)) {
        xon = 0;
        xPos = (width - Woffset);
    }
}
function Startmove() {
    FOBJ=document.getElementById("_FloatWindowDiv");
    if(FOBJ){
        FOBJ.style.top = yPos;
        FOBJ.visibility = "visible";
        floatHandle = setInterval('changePos()', floatDelay);
    }
}
Startmove();