While Loop help

[jr24460]

I was wondering if someone could show me how to set this "while loop" problem up. I am sort of new to c++ and would appreciate any help.

here is the program description. Write a program which uses a while loop to compute the average of a number of test scores. use -999 as a sentinel to indicate the end of the test scores. the program should prompt the user to enter a test score and then input the test score and add it to a total and increment the test score count by one. If the user enters the sentinel value the program should exit the loop,divide the total by the count and display the average.

I am not looking for a direct answer i just need to be pointed in the right direction. any help would be appreciated thanks!

[Esslercuffi]

while( score != -999 )
{
	// get score from user
	// if score !valid
	//	continue;
	// if score == -999
	//	break
	// 
	// accumulate total and keep track of # of scores
}

// calculate average and output results.