Your new function, which still has the { } problem jonsca pointed out, will return immediately after the first number is read in, depending on whether it meets the 10-500 test or not.
You should construct the loop to read in six times, and test if the new number is outside the 10-500 range. If so, set a variable to indicate so. After the loop, test that variable to see if there was an out of range number, returning true if so, false otherwise.
In the enhancements to the function, to indicate specifically if number less than 10 or greater than 500 was entered, you'll need to pass two boolean variables by reference to the function, and they will initially be set false, and be set true any time a qualifying value is entered.
I think the purpose of this exercise, besides a simple loop, is to see how you can pass one piece of information back by the return value, but to get multiple pieces of information you must use multiple parameters passed by reference.
The general model for you loop should be something like:
while ( loop still needs to run )
{
get input
if( input meets test )
set flag
}
if( flag set )
return true;
else
return false;
}