var gradientColors:Array = [0xFF00FF,0x33CCCC];
var gradientAlphas:Array = [1,1];
var gradientRatios:Array = [0,255];

var matrix:Matrix = new Matrix();
matrix.createGradientBox(120, 120, 45);
graphics.beginGradientFill(GradientType.RADIAL, gradientColors, gradientAlphas, gradientRatios, matrix);
graphics.drawCircle(60, 60, 60);