Affichage canvas ne fonctionne pas

window.onload = function() {
var c = document.getElementById("rendu");
var ctx = c.getContext("2d");
 
var skin = new Image();
skin.src = "../assets/sprites/character/skin/"+document.getElementById('sex').getAttribute('value')+"/skin/"+document.getElementById('skin').getAttribute('value')+".png";
 
var eyes = new Image();
eyes.src = "../assets/sprites/character/skin/"+document.getElementById('sex').getAttribute('value')+"/eyes/"+document.getElementById('eyes').getAttribute('value')+".png";
 
var nose = new Image();
nose.src = "../assets/sprites/character/skin/"+document.getElementById('sex').getAttribute('value')+"/nose/"+document.getElementById('nose').getAttribute('value')+document.getElementById('skin').getAttribute('value')+".png";
 
var ears = new Image();
ears.src = "../assets/sprites/character/skin/"+document.getElementById('sex').getAttribute('value')+"/ears/"+document.getElementById('ears').getAttribute('value')+document.getElementById('skin').getAttribute('value')+".png";
 
var hair = new Image();
hair.src = "../assets/sprites/character/skin/"+document.getElementById('sex').getAttribute('value')+"/hair/"+document.getElementById('hair').getAttribute('value')+"/"+document.getElementById('haircolor').getAttribute('value')+".png";
 
 
  //Rendu
  function draw() {
  ctx.drawImage(skin,0,0,64,64,0,0,64,64);
  ctx.drawImage(eyes,0,0,64,64,0,0,64,64);
  ctx.drawImage(nose,0,0,64,64,0,0,64,64);
  ctx.drawImage(ears,0,0,64,64,0,0,64,64);
  ctx.drawImage(hair,0,0,64,64,0,0,64,64);
   
  }
 
draw();
      
  
 
}