Gradiant on a UIView to transparant

uiview_gradiant.m

CALayer *viewLayer = UIVIEW.layer;
CAGradientLayer *gradientLayerView = [[CAGradientLayer alloc] init];
[gradientLayerView setFrame:[UIVIEW frame]];
[gradientLayerView setPosition:CGPointMake(UIVIEW.frame.size.width / 2, UIVIEW.frame.size.height / 2)];
[gradientLayerView setMasksToBounds:NO];
[gradientLayerView setColors:[NSArray arrayWithObjects:
						 (id)[[UIColor colorWithWhite:0.0 alpha:1.0] CGColor], 
						 (id)[[UIColor colorWithWhite:0.0 alpha:0.0] CGColor], nil]];

[gradientLayerView setStartPoint:CGPointMake(0.5, 0.92)];
[gradientLayerView setEndPoint:CGPointMake(0.5, 1)];
	
[viewLayer setMask:gradientLayerView];
[viewLayer setMasksToBounds:NO];
[gradientLayerView release];