Simple function to write a single pixel to a canvas element

pixel.js

//Copied from http://stackoverflow.com/q/4899799/119909
function pixel(x,y){
    d[0]   = 255;//r
    d[1]   = 0;//g
    d[2]   = 0;//b
    d[3]   = 255;//a
    ctx.putImageData( id, x, y );
}
var ctx = document.getElementById('c').getContext('2d');
var id = ctx.createImageData(1,1);
var d = id.data;