var topMargin = 150 
var slideTime = 1200
var ns6 = (!document.all && document.getElementById); 
var ie4 = (document.all);
var ns4 = (document.layers);
window.setInterval("main()", 10) 

function floatObject() { 
if (ns4 || ns6) {
findHt = window.innerHeight; 
} else if(ie4) {
findHt = document.body.clientHeight;
}
} 

function main() { 
if (ns4) { 
this.currentY = document.floatLayer.top; 
this.scrollTop = window.pageYOffset;
mainTrigger();
} else if(ns6) {
this.currentY = parseInt(document.getElementById('floatLayer').style.top); 
this.scrollTop = scrollY;
mainTrigger(); 
} else if(ie4) { 
this.currentY = floatLayer.style.pixelTop;
this.scrollTop = document.documentElement.scrollTop; 
mainTrigger();
} 
} 
function mainTrigger() { 
var newTargetY = this.scrollTop + this.topMargin 
if ( this.currentY != newTargetY ) { 
if ( newTargetY != this.targetY ) { 
this.targetY = newTargetY
floatStart(); 
} 
animator(); 
} 
} 
function floatStart() { 
var now = new Date() 
this.A = this.targetY - this.currentY 
this.B = Math.PI / ( 2 * this.slideTime ) 
this.C = now.getTime() 
if (Math.abs(this.A) > this.findHt) { 
this.D = this.A > 0 ? this.targetY - this.findHt : this.targetY + this.findHt 
this.A = this.A > 0 ? this.findHt : -this.findHt 
} else { 
this.D = this.currentY 
} 
} 
function animator() { 
var now = new Date() 
var newY = this.A * Math.sin( this.B * ( now.getTime() - this.C ) ) + this.D 
newY = Math.round(newY) 
if (( this.A > 0 && newY > this.currentY ) || ( this.A < 0 && newY < this.currentY )) { 
if ( ie4 )floatLayer.style.pixelTop = newY 
if ( ns4 )document.floatLayer.top = newY
if ( ns6 )document.getElementById('floatLayer').style.top = newY + "px" 
} 
}