function ChangeGroupSize() {

	var form = document.getElementById("enrollform");
	var numberinparty = document.getElementById("Number_in_party");
    var nadditional = numberinparty.selectedIndex;
	var captionrow = document.getElementById("captionRow");
	var addrow1 = document.getElementById("additionalRow1");
	var addrow2 = document.getElementById("additionalRow2");
	var addrow3 = document.getElementById("additionalRow3");
	var addrow4 = document.getElementById("additionalRow4");
	var addrow5 = document.getElementById("additionalRow5");
	var addrow6 = document.getElementById("additionalRow6");
	var addrow7 = document.getElementById("additionalRow7");
	var addrow8 = document.getElementById("additionalRow8");

	if (nadditional < 8) {
		addrow8.style.display = 'none';
	}
	else {
		addrow8.style.display = '';
	}
		
	if (nadditional < 7) {
		addrow7.style.display = 'none';
	}
	else {
		addrow7.style.display = '';
	}

	if (nadditional < 6) {
		addrow6.style.display = 'none';
	}
	else {
		addrow6.style.display = '';
	}
	
	if (nadditional < 5) {
		addrow5.style.display = 'none';
	}
	else {
		addrow5.style.display = '';
	}
	
	if (nadditional < 4) {
		addrow4.style.display = 'none';
	}
	else {
		addrow4.style.display = '';
	}
	
	if (nadditional < 3) {
		addrow3.style.display = 'none';
	}
	else {
		addrow3.style.display = '';
	}
	
	if (nadditional < 2) {
		addrow2.style.display = 'none';
	}
	else {
		addrow2.style.display = '';
	}
	
	if (nadditional == 0) {
		captionrow.style.display = 'none';
		addrow1.style.display = 'none';
	}
	else {
		captionrow.style.display = '';
		addrow1.style.display = '';
	}
	
	return true;
}