function calculateCost() {
	grandTotal=0;
	total = 0;
	if( $('#issue_q1_2007').attr('checked') ) { total++; }
	if( $('#issue_q2_2007').attr('checked') ) { total++; }
	if( $('#issue_q3_2007').attr('checked') ) { total++; }
	if( $('#issue_q4_2007').attr('checked') ) { total++; }
	if( $('#issue_q1_2008').attr('checked') ) { total++; }
	if( $('#issue_q2_2008').attr('checked') ) { total++; }
	if( $('#issue_q3_2008').attr('checked') ) { total++; }
	if( $('#issue_q4_2008').attr('checked') ) { total++; }
	if( $('#issue_q1_2009').attr('checked') ) { total++; }
	if( $('#issue_q2_2009').attr('checked') ) { total++; }
	if( $('#issue_q3_2009').attr('checked') ) { total++; }
	if( $('#issue_q4_2009').attr('checked') ) { total++; }
	
	
	if( total > 1 ) {
		grandTotal = 15 + ( total - 1 ) * 10;
	}
	else {
		grandTotal = 15 * total;
	}
	$('#total').val('$'+grandTotal+'.00');
	$('#totalcost').val(grandTotal);
	if( grandTotal > 0 ) {
		$('#purchase').slideDown();
	}
	else {
		$('#purchase').slideUp();
	}
}