Code with sample:
<script Language="JavaScript">
r=0
g=0
b=0
function pset(x,y,wi,he)
{
document.write ("<img src='1x1.gif' style='z-index:-10; position:absolute; left:"+x+";top:"+y+";width:"+wi+";height:"+he+";background:rgb("+r+","+g+","+b+")'>")
}
kx=400
ky=400
x0=(window.screen.width-20)/2
y0=400
r=g=b=0
pset(x0-kx/2,y0,kx,2)
pset(x0,y0-ky/2,2,ky)
g=255
for(x=-kx/4;x<kx/4;x++)
{
y=x*x/kx*8
pset(x+x0,-y+y0,2,2)
}
g=0
r=255
for(x=-kx/2;x<kx/2;x++)
{
y=Math.sin(x/kx*20)*ky/10
pset(x+x0,-y+y0,2,2)
}
r=0
b=255
for(i=-100;i<100;i=i+0.5)
{
x=Math.cos(i/100*3.15)*kx/4
y=Math.sin(i/100*3.15)*ky/4
pset(x+x0,-y+y0,2,2)
}
</script>
1x1.gif is a 1 pixel square transparent gif. To download a copy from this server, right click on this and select "Save as..."
For discussion, and further information about this script, see imgdraw.htm