Syntax errors corrected

// http://www.goracertech.com/blog/spring-selector/
add_action('gform_pre_submission', 'ch_total_quiz_values');
function ch_total_quiz_values ($form) {
	// change the number 20 here to your form ID
	// if this is not form 20, don't do any processing
	if($form['id'] != 4)
		return $form;

	// get RZR model
	$rzr_model = $_POST['input_1'];

	// normalize rzr model to score value
	if($rzr_model == 5) {
		$_POST['input_1'] = -300; // RZR 4 800
	}

	// otherwise ...
	$score = 0;

	// my radio button inputs are numbered 1 to 20.  Change the beginning
	// and ending number in this loop to match your actual input numbers
	for($i=1; $i<=19; $i++) {
		// add the value of the $_POST value for input 1 to input 20
		$input  = 'input_' . $i;
		$score += rgpost($input);
	}

	// update the hidden 'Score' field with our calculated score
	$_POST['input_20'] = $score;

	// set the recommendation
	if($score < 400) {
		$_POST['input_21'] = 'MEDIUM RATE';
	}
	else {
		$_POST['input_21'] = 'HEAVY RATE';
	}

	// set the recommendation link
	switch($rzr_model) {
		case 1: // RZR 800 50 inch STD
			$_POST['input_23'] = nl2br("Standard RZR 50 inch Replacement Springs Kit.\r\n<a href='http://www.goracertech.com/rzr-std-replacement-springs.html'>Buy them here</a>.");
			break;
		case 2: // RZR 800 50 inch Walker evans edition
			$_POST['input_23'] = nl2br("Standard RZR 50 inch Replacement Springs Kit.\r\n<a href='http://www.goracertech.com/rzr-std-replacement-springs.html'>Buy them here</a>.");
			break;
		case 3: // RZR S 800 with fox podium shocks
			$_POST['input_23'] = nl2br("RZR S Replacement Springs Kit - Fox Podium Dual Rate\r\n<a href='http://www.goracertech.com/rzr-s-replacement-springs.html'>Buy them here</a>.");
			break;
		case 4: // RZR S 800 with sachs shocks
			$_POST['input_23'] = nl2br("RZR S Sachs Replacement Springs - 2011+ RZR S\r\n<a href='http://www.goracertech.com/rzr-s-sachs-replacement-springs-2011-rzr-s.html'>Buy them here</a>.");
			break;
		case 5: // RZR 4 800
			$_POST['input_23'] = nl2br("RZR 4 800 Replacement Springs Kit - Dual Rate\r\n<a href='http://www.goracertech.com/rzr-4-replacement-springs.html'>Buy them here</a>.");
			break;
		case 6: // RZR XP 900
			$_POST['input_23'] = nl2br("RZR XP 900 Dual Rate Springs Replacement Kit\r\n<a href='http://www.goracertech.com/products/featured/rzr-xp-900-dual-rate-spring-replacement-kit.html'>Buy them here</a>.");
			break;
	}

	return $form;
}
?>