How I do a detection between two animations?

Hello!

I want to know how I do to create a detection between two ou three animations??

I want to do a Row of people, but if the frist people are buy, the second people stop and wait.

But if don't exist any people, then the people go to the cash register and buy...

I don't know how I create a detection...

Obs: the row can't show in the scene, the people appear one at a time.

Thanks. <img src="smileys/smiley10.gif" border="0" align="middle" />

Something like this?

click sprites from left to right to tell them to buy..

Well, I want that the people go to buy, if two conditions are respected:

1� - the price

    if price > 3 : only two people buy

if the price <3 : more people buy...

the square search alone , you can't control the square, you can only control the variables ( price, wearm)...

thanks for you example.