function checkWheelValues() {
	
	var frm = document.wheelSearch;
	var options = 0;
	
	if (frm.wheelDiameter.options[frm.wheelDiameter.selectedIndex].value != 0) {
		options += 1;
	}

	if (frm.wheelWidth.options[frm.wheelWidth.selectedIndex].value != 0) {
		options += 1;
	}
	
	if (frm.bp.options[frm.bp.selectedIndex].value != '') {
		options += 1;
	}
	
	if (frm.finish.options[frm.finish.selectedIndex].value != '') {
		options += 1;
	}
	
	if (frm.manufacturer.options[frm.manufacturer.selectedIndex].value != '') {
		options += 1;
	}
	
	if (options < 2) {
		alert('You must select at least two wheel search fields to continue');
		return false;
	} else {
		return true;
	}
}