Edit in JSFiddle

window.onload = function () {
    
    //create paper
    var paper = Raphael("canvas");

    //Draw Circle
    paper.circle(150,50,50);    
    paper.circle(50,50,50);
    paper.circle(150,150,50);    
    paper.circle(50,150,50);
    
    paper.circle(100,100,100);
    
}

<div id="canvas"></div>

body,html
{
    height:100%;
    margin:0;
}

#canvas 
{
    height:100%;
    background:#aaa;
}