How do i make things sense proximity

I am doing an interactive alice program for school where things are raining down from buildings to beach balls (set to invisible) the goal is to make it to the other side of a passage with the buildings creating barriers on the left and right sides without getting hit. It is a first person game, so i set the arrow keys to control the camera. How do i get the world to sense that the camera has been hit by one of the falling objects?

Click on camra.
Then go to the properties of camra.
Then set the solid thing to 100%.

If you cant then "I Dont Know"

I don't see that setting,
but thanks anyways

I figured it out

incase any one else wants to know

you need to make an if statement saying that
If the object is within x meters of the camera then
do your a lose method

the thing is you need to constantly check whether this is happening
you do this by enclosing the if statement in an infinity loop (courtesy daniel childers)
then incase that in a do together with the rest of the methods that make your world work

just make sure that if these other methods must be done in order to put them into a do in order within the do together

this in pseudocode

do together
do loop infinity times
if statements (to check for proximity)
do in order
the rest of your methods

[x2495iiii]

That's right, but remember to be careful with "do infinity times" methods, they can make your other methods run slowly or stop them from running entirely (if used improperly).

cool
good to know
thanks

I believe I posted a tip like this in my old account...

http://www.alice.org/community/showthread.php?t=1548