function stampduty(dutyform) 
{
	var amount = dutyform.amount.value;

	if (amount == "") 
	{
		amount = 0;
		window.alert("You have not entered a value!");
	}


	if ((amount % 100) != 0 ) 
	{
		var mod = eval(100-(amount % 100));
		amount = -(-amount - mod);
	}


	if (amount <= 14000) {
		var duty = eval((amount/100)*1.25);
	}

	else if ((amount > 14000) && (amount <= 30000)) {
		var duty = eval((((amount - 14000)/100)*1.5) + 175);
	}

	else if ((amount > 30000) && (amount <= 80000)) {
		var duty = eval((((amount - 30000)/100)*1.75) + 415);
	}

	else if ((amount > 80000) && (amount <= 300000)) {
		var duty = eval((((amount - 80000)/100)*3.5) + 1290);
	}

	else if ((amount > 300000) && (amount <= 1000000)) {
		var duty = eval((((amount - 300000)/100)*4.5) + 8990);
	}

	else {
		var duty = eval((((amount - 1000000)/100)*5.5) + 40490);
	}	


	duty = Math.round(duty);
	dutyform.duty.value = duty;
	return false;
}