A simple animated text stereogram in Javascript

<?php echo "

#box1{
font-family: monospace;
float: left;
}
#box2{
font-family: monospace;
margin-left: 135px;
}
#fly1{
margin-left: 35px;
}
#fly2{
margin-left: 30px;
}
“;
?>

Make sure you can view stereograms or practice well or it will not make sense.
// <![CDATA[
var i=35;
var dir="right";
var fly1=document.getElementById("fly1");
function varyI(){
fly1.style.marginLeft=i+"px";
if(dir=="right"){
if(i0){
i–;
}
else{
dir=”right”;
}
}
cb();
}
function cb(){
setTimeout(varyI, 80);
}
varyI();
// ]]>