var zoomlevel = 0;
function magni_inc()
{
 if(zoomlevel > 1) return;
 else zoomlevel++;
 var currentSize = parseInt(document.body.style.fontSize);
 if(!currentSize) currentSize = 11;
 currentSize = currentSize + 2;
 document.body.style.fontSize = currentSize+"px";
}

function magni_dec()
{
 if(zoomlevel < -1) return;
 else zoomlevel--;

 var currentSize = parseInt(document.body.style.fontSize);
 if(!currentSize) currentSize = 11;
 currentSize = currentSize - 2;
 document.body.style.fontSize = currentSize+"px";
}