I'm trying to alter an SVG elements viewbox in JavaScript. Basically, I'm drawing a binary search tree, and when it gets too wide, I want to alter the viewbox to zoom out so that the tree fits in the window. I'm currently using:

if(SVGWidth>=1000){

  var a = document.getElementById('svgArea');

  a.setAttribute(viewbox,0 0  + SVGWidth +  300);

}

The HTML is:

<svg id=svgArea xmlns=w3.org/2000/svg; xmlns:xlink=w3.org/1999/xlink; width=1000 height=300 viewBox=0 0 1000 300>

I've also tried using setAttributeNS('null',...) but that didn't seem to work either. One strange thing I've noticed is that when I alert(a) it gives [object SVGSVGElement] which seems strange. Any help is appreciated.