Increasing the speed for a certian frames in Flash Cs5 using Action Script 3

Question

I have 60 frames I want to increase the fps value for frames from 20 to 30, and the remaining frames fps value should remain the same
Using Action Script 3 or Action Script 2
Thank you and regards

Answer 1

I have found a script online
Q: How can I speed the frame rate or slow it down when the movie is playing? For example, I would like to slow the frame rate from the default of 20 fps to 15 fps from frame #80 to frame #150. Then frame rate should speed back up to 20 fps after frame #151, (fps = frames per second).
A: One way is to use “interval”. An example of changing the speed of the movie from frame #80 to frame #150 is shown below.
Create a key frame at frame #80 and place this script:
var fps:Number = 80;
var intervalID:Number = setInterval(this, “advanceFrame”, 1000/fps);
stop();
function advanceFrame() {
clearInterval(intervalID);
gotoAndStop(_currentframe+1);
if (_currentframe<151) {
intervalID = setInterval(this, “advanceFrame”, 1000/fps);
} else {
play();
I have changed the values from 80 to 20 and currentframe value to 30
I get syntax error
at :
intervalID = setInterval(this, “advanceFrame”, 1000/fps);
and
var intervalID:Number = setInterval(this, “advanceFrame”, 1000/fps);
In flash cs5