JS cant call method drawImage of null

Question

I got this lil file

/* WaterBall API notification model by Makerimages*/
function WBNotification(x,y,icon,text)
{
this.background="/WBGraphics/WBNotification.png";
this.x=x;
this.y=y;
this.icon=icon;
this.text=text;






this.draw=function()
{

var canvas = document.createElement('canvas');
canvas.id="WBNotificationArea";
canvas.width=88;
canvas.height =43;
document.body.appendChild(canvas);
cvs=document.getElementById("WBNotificationArea");
var context=cvs.getContext();
context.drawImage(this.background,this.x,this.y);
}
 return this;
}

and I use it like this

site=new waterContainer();
site.notifications[0]=new WBNotification(10,10,null,"hello there!");
site.notifications[0].draw()

everything works, but the this.draw() says(in chrome`s script reading thingy) that it cannot call method drawImage of null, how could I fix it?

Answer 1

You need to pass in the string "2d" to getContext() .

The function will return null if the context-type supplied is not available.