function purDiscount(){
	document.getElementById('discount_pur').value = document.getElementById('discount_pur').value.toUpperCase();
	if (document.getElementById('discount_pur').value in {JLG18:1, jlg18:1}) {
		document.getElementById('purPrice').innerHTML = '£18.00';
		document.getElementById('purText').innerHTML = 'Discount applied';
	} else {
		document.getElementById('purPrice').innerHTML = '£22.00';
		document.getElementById('purText').innerHTML = 'Incorrect code';
	}
}