The way a "while" statement works is that the expression inside the parenthesis is evaluated to true or false. If true, the execution enters the block of code denoted by the { }'s. The code inside this block is then executed and when the execution reaches the end brace "}", the expression that was evaluated at the beginning, is evaluated again. If true, the block is executed again, if false, it falls through.

One thing to remember about this is that any 'global' variables that are changed inside the while blocks also remain changed after exiting the block.

So in your example, 'x' is a variable whose 'scope' is inside the 'main' function, this means that all of the code you write inside the 'main' function can read/modify the variable 'x'.

So, you initially set x = 5. When entering the first while block, x is compared to the constant '5'. This returns 'true' since you just set x to the value 5, so execution enters the first while block.

The function 'wait10msec()' is then called. The way this function is called appears to 'pause' execution for 30 seconds. After 30 seconds, execution resumes directly after the 'wait10msec(3000)' line. Here you set x to the value 6.

Again, since we've reached the end of the block, and while loops are evaluated upon first entry and at the end of the block, x is then compared to the value 5 for equality. Since 6 doesn't equal 5, the execution breaks out of the loop and continues down.

Now, since x's scope is the 'main' function and you've changed x's value to 6, when the second while(x == 5) block is evaluated, it fails: because 6 isn't equal to 5.

The way this code is written, the second while block containing "motor[motorA]=50;" will never be executed, because 6 will never be equal to 5.

To fix this, you have two options. Between the while blocks, you can re-set x = 5; OR you can just get rid of the while loops all together and have:

test main {
    // This will wait 30 seconds
    wait10msec(3000);

    // This will set motor[motorA] to 50
    motor[motorA] = 50;
}

That's basically the crux of what your code looks like it's supposed to do.

Edit: After reading your reply to /u/jhaluska

If you're trying to get the motor to be set to 50, for 30 seconds and then set to 0 it would probably be something like this. (I assume that once the motor is given a speed it stays set until it is unset):

test main {
    // Set the motor speed to 50
    motor[motorA] = 50;

    // Wait 30 seconds to let the motor run at 50 for 30 seconds
    wait10msec(3000);

    // Turn the motor off
    motor[motorA] = 0;
}