shadowColor : Colour of shadow on Canvas

void gctx.shadowColour='#ff00ff';

var my_canvas=$('#my_canvas').get(0)
var gctx = my_canvas.getContext("2d");
gctx.beginPath()
gctx.rect(20,20,150,100);
gctx.lineWidth=8;
gctx.shadowColor = '#00ff00';
gctx.shadowOffsetX=20;
gctx.shadowOffsetY=20;
gctx.shadowBlur = 15;
gctx.stroke();