JS DOM Style Toggle SRC W/ No CSS!!!!!

<center>
<script>
var v=0;
function styleToggle() {
v++;
if (v!=2){
var x =document.body.style;
document.body.style.fontSize = "29px";
document.body.style.color= "red";
document.body.style.background= "#000000";
}
if (v==2){
v=0;
var x =document.body.style;
document.body.style.fontSize = "16px";
document.body.style.color= "black";
document.body.style.background= "#FFFFFF";
}
}
</script>

<button onclick="styleToggle()">Click Me!</button>
<h2><p>YO!!!!!!</p></h2>
</body>
</center>