Use of callback parameter in JS functions

I'm trying to use a callback parameter (I do not know if it's the correct term here) inside my constructor, which calls a function I defined, but every time I try to run the code it displays an error in the console.

Here is the button builder code:

function Botao(x, y, w, h, canvas, callback,color) {
this.x = x;
this.y = y;
this.w = w;
this.h = h;
this.cb = callback;
this.color = color;   

//render do botão.
this.render = function () {
 canvas.context.fillStyle = color || '#000'; // cor
 canvas.rect(this.x,this.y,this.w,this.h); // cria o retangulo(botão)
}

// verifica se o click foi na área do botao.
this.ontarget = function (pos) {      
 if (pos.x > this.x && pos.x < (this.x + this.w) && pos.y > this.y && pos.y <   (this.y + this.h)){
  this.cb(); // <-- meu problema/duvida!
  };  
}

and here is the code where I use it:

var teste = new Canvas(400,300,teste, 0); // cria o canvas


var bt1 = new Botao(100,100,100,100, teste, function()  {console.log("teste");}); //cria o botao



function run() {
teste.upC();//renderiza o botão

bt1.render();// renderiza o botao.
window.requestAnimationFrame(run);
}
run();


function click(evt) {
 var rectNav = teste.rectNav; ; //obtêm as coordenadas do mouse na janela do   cliente.
 var pos = {
  x: evt.clientX - rectNav.left,
  y: evt.clientY - rectNav.top
 }; 

 bt1.ontarget(pos); //detecta se o click foi no botão 
}  


cEvent('click', click);

As you can see, this is a button, where when clicking it it should return the function it assigns to callback at the time I created it, but I can not get it to work, I am using the parameter incorrectly? The function will not work in this case of the constructor?