//眼珠转动JAVASCRIPT代码
//Created by He Yi on 2008-05-30
//华中科技大学网络应用研发中心（NADC）
document.body.onmousemove = function roll(e)
{
	e=window.event||e;
    var startTop = 11;
    var startLeft = 56;
    var startR = 10;
    
    var eye = document.getElementById("eye");
    
    var eyeTop = 0;
    var eyeLeft = 0;
    var posX=e.x||e.pageX;
	var posY=e.y||e.pageY;
    var xLength = document.body.scrollLeft + posX - startLeft;
    var yLength = document.body.scrollTop + posY - startTop;
   
    
    var rLength =Math.sqrt( xLength * xLength + yLength * yLength);
    if(rLength >= 400)
    {
        eyeTop = startTop + (yLength * startR / rLength);
        eyeLeft = startLeft + (xLength * startR / rLength);
    }
    else if(rLength<10)
    {
        return;
    }
    else
    {
        eyeTop = startTop + yLength*startR/400;
        eyeLeft = startLeft + xLength*startR/400;
    }
    eye.style.top = eyeTop+"px";
    eye.style.left = eyeLeft + "px";
}