If, if else, if else if . These are conditional statments with the same concept. If a condition is true, Flash should execute the action. If it is not true, Flash will ignore the section of code and move on.

examples:
if (classSize>10){
get more books;
}else if (classSize<10){
return books;
}else{
get classSize;
}

This file shown below uses a conditional statement to see if the ball is off the canvas and if it is, it resets it to back on the canvas.

download the conditional file example shown above (file name: conditional.fla)
right click on the file (control-click for Mac) and select to download to your drive.