bezier.js Example File

 function drawShape() {
 // get the canvas element using the DOM
 var canvas = document.getElementById('tutorial');

   // Make sure we don't execute when canvas isn't supported
   if (canvas.getContext){

     // use getContext to use the canvas for drawing
     var ctx = canvas.getContext('2d');

     // Draw shapes

     ctx.beginPath();
     ctx.moveTo(75,40);
     ctx.bezierCurveTo(75,37,70,25,50,25);
     ctx.bezierCurveTo(20,25,20,62.5,20,62.5);
     ctx.bezierCurveTo(20,80,40,102,75,120);
     ctx.bezierCurveTo(110,102,130,80,130,62.5);
     ctx.bezierCurveTo(130,62.5,130,25,100,25);
     ctx.bezierCurveTo(85,25,75,37,75,40);
     ctx.fill();
     ctx.globalAlpha = 0.5;
  }
 }

 drawShape();