In this Macromedia Flash tutorial you will see how to make a great text apperance effect

1.
Start with an empty stage with a black background color.
In the time line layers panel make 3 layers name them text1, text2 and text3.

2.
Now in the layer text1 type in the letter H, in text2 type e and in text3 type y.
For each layer make a new keyframe at frame 65 (the end of our animation)

3.
in the layers panel, create a new layer under each text layer, and name them effect1, effect2, effect3.
Insert a new keyframe at frame 5 for the effect 1.

4.
Draw a white rectangle with the rectangle tool. (it should fit almost the the edges of the hight of the stage.
Right click the rectangle shape, and convert it to a movie clip.

Go to your new movie clips filters properties, give it a blur effect as shown in the image below.

5.
Now make a new keyframe for effect1 at frame 20.
With the free transform tool scale the rectangle down as shown in the image below.
Right click between frame 5 and 20, and make a motion tween.

6.
For the text1 layer drag the keyframe to frame 21, so the letter first appears when the effect is done, as shown below.

7.
Insert a new keyframe at frame 22 for the effect2 layer.
Draw a white rectangle with the rectangle tool. (it should fit almost the the edges of the hight of the stage.
Right click the rectangle shape, and convert it to a movie clip.

Give it a blur filter as in step 4.

8.
Make a new keyframe at frame 36.
With the free transform tool scale the rectangle down as shown in the image below.
Right click between frame 22 and 36, and make a motion tween.

9.
For the text1 layer drag the keyframe to frame 37, so the letter first appears when the effect is done, as shown below.

Repeat these steps for the last text and effect layer and you will end up with the result I have.

for reference I have made an image of my final time line.