// Purpose
//	Used to calculate the sum of a sequence of digits.
// Parameters
//	DigitSequence (String) = The digit sequence we are working with.
// Return (Number)
//	Returns the sum of all digits in the specified sequence.
// Entry Conditions
//	Each character must be a valid digit between 0 and 9 or function may crash.
// Version History
//	1.0 4/25/2004 Tested by Russ Tanner
//---
function SumOfDigitSequence($DigitSequence) {

	// Initiate variables
	$R = 0; // Return buffer

	// Main loop: Sum all digits in the sequence
	for ($C = 0, $lenDS = strlen($DigitSequence); $C < $lenDS; $C++) {
		$R = $R + $DigitSequence{$C}; // Accumulate the sum
	}

	// Return the result
	return $R;

}