Repeat this script?

Loops

HOLD UP! Before we get into repeating your code, it's probably safe to assume that your code is WAY to long for what it could actually be.

To give a quick example of how we can change your code, let's first do something else.

Let's make a script that prints every number from 1 to 10:

print(1)
print(2)
print(3)
print(4)
print(5)
print(6)
print(7)
print(8)
print(9)
print(10)

Now, the above code does indeed get the job done.

However, we can make the code a LOT shorter.

Take a look at this:

for i = 1, 10 do
print(i)
end

What was done above is called a loop. It allows you to go through a series of value(s) very easily. Basically, it sets the variable 'i' to 1. Each time the chunk of code between the 'for' and the 'end' has finished running, 'i' will increase by '1'. It does this till it reaches 11. That's why the code will print every number from 1 - 10 inclusive.

We can even change the increment by adding a third number!

for i = 1, 10,2 do
print(i)
end

The third number will print the code at counts of '2'.

So it will print, 1, 3, 5, 7, 9, 10

Using What We've Learnt

Now, let's make your code shorter AND repeat.

for transparency = .1,1,.1 do
workspace.Base.Transparency = transparency
wait(.5)
end
workspace.Base.CanCollide = false
wait(.5)
workspace.Base.CanCollide = true
for transparency = 1,.1,-.1 do
workspace.Base.Transparency = transparency
wait(.5)
end

Great! We've shortened your code by using a loop, but let's make it repeat forever. We can use a while loop to achieve this.

while true do
for transparency = .1,1,.1 do
workspace.Base.Transparency = transparency
wait(.5)
end
workspace.Base.CanCollide = false
wait(.5)
workspace.Base.CanCollide = true
for transparency = 1,.1,-.1 do
workspace.Base.Transparency = transparency
wait(.5)
end
end

Basically, a while loop will keep repeating if whatever you put between the 'while' and 'do' is true. So if we put 'true', then it will repeat forever since true is always true. [Sorry if that sounds weird]

For more on loops

There are a lot of sources that teach loops. Loops are a highly essential part to certain aspects of coding.

Helpful Links

http://wiki.roblox.com/index.php?title=Basic_Scripting

http://wiki.roblox.com/index.php?title=Loops

http://wiki.roblox.com/index.php?title=Absolute_beginner%27s_guide_to_scripting

You code is extremely inefficient, I suggest a for loop and a while loop..

Brick = game.Workspace.Base
for i = (0, 1, 0.1) -- This is saying go from 0 to 1 in steps of 0.1, so this will loop 10 times, and "i" will get gradually bigger, increasing the transparency on the next line.
    Brick.Transparency = i
    wait(0.5)
end

These 4 lines of code will make your Brick's transparency go from 0 to 1, gradually over the course of 5 seconds, in these 4 lines we have done your lines 2 - 21.

The next 3 Lines are fine:

Brick.CanCollide = false
wait(0.5)
Brick.CanCollide = true

Then the transparency back down again:

for i = (1, 0, -0.1)
    Brick.Transparency = i
    wait(0.5)
end

Now to make this loop forever, put it in a while loop, these loops loop foreveruntil told to break.

Example:

while true do
    print ("Hello World!")
end

This will print Hello World! forever!

So your full code is:

Brick = game.Workspace.Base

while true do
    for i = (0, 1, 0.1) -- This is saying go from 0 to 1 in steps of 0.1, so this will loop 10 times, and "i" will get gradually bigger, increasing the transparency on the next line.
        Brick.Transparency = i
        wait(0.5)
    end

    Brick.CanCollide = false
    wait(0.5)
    Brick.CanCollide = true

    for i = (1, 0, -0.1)
        Brick.Transparency = i
        wait(0.5)
    end
end

With these efficient loops we have made your 43 lines of code into 17

This is easy, just do

repeat
game.workspace.Base.Transparency=0.1
wait(0.5)
game.workspace.Base.Transparency=0.2
wait(0.5)
game.workspace.Base.Transparency=0.3
wait(0.5)
game.workspace.Base.Transparency=0.4
wait(0.5)
game.workspace.Base.Transparency=0.5
wait(0.5)
game.workspace.Base.Transparency=0.6
wait(0.5)
game.workspace.Base.Transparency=0.7
wait(0.5)
game.workspace.Base.Transparency=0.8
wait(0.5)
game.workspace.Base.Transparency=0.9
wait(0.5)
game.workspace.Base.Transparency=1
wait(0.5)
game.workspace.Base.CanCollide=false
wait(0.5)
game.workspace.Base.CanCollide=true
game.workspace.Base.Transparency=0.9
wait(0.5)
game.workspace.Base.Transparency=0.8
wait(0.5)
game.workspace.Base.Transparency=0.7
wait(0.5)
game.workspace.Base.Transparency=0.6
wait(0.5)
game.workspace.Base.Transparency=0.5
wait(0.5)
game.workspace.Base.Transparency=0.4
wait(0.5)
game.workspace.Base.Transparency=0.3
wait(0.5)
game.workspace.Base.Transparency=0.2
wait(0.5)
game.workspace.Base.Transparency=0.1
wait(0.5)
game.workspace.Base.Transparency=0
wait(0.5)

until 9 + 10 == 21