let me describe my problem:

I'm using Kinect and the only thing it does (that i want it to do) is recognize a user and define a unic center point for him. Then I send the relative coordinates of that point (that accompanies the user's movements) via OSC to Processing. 

The thing I want it to do is: there is a given number of balloons hovering in the air (spheres) and when a user appears, one balloon is chosen (randomly) and it will follow the user and then, given a certain time, it will explode. For this, there are some kind of conditions, like I don't want that other balloon starts following the user until de last one explode, or better, I only want to attribute a single balloon for each time a user appear.

By now I'm having a few problems on getting that, because the condition that I definied to recognize the user maybe is wrong (if xUser and yUser are in the window area) and I can't stop that verification so a balloon after another is exploding while that condition is true (and it is, because the same user is still there). In other hand, I don't think I have a variable or a method to only detect that a user entered.

For who wants to help me I can send the code in order to be better analyzed.

Thanks in advance