function calculateform() {
	var u = document.calculator.number_stations.value;
	var h = document.calculator.hours_per_day.value;
	var d = document.calculator.days_per_week.value;
	var e = document.calculator.encoding.value;

	if(document.calculator.number_stations.value == '' || document.calculator.number_stations.value < 1) {
		alert("Please enter a number of 1 to 32 for the number of telephone stations.");
		document.calculator.number_stations.value = '1';
	}

	else if(document.calculator.number_stations.value < 1 || document.calculator.number_stations.value > 32){
		alert("Sorry, the maximum number of telephone stations supported is 32");
		document.getElementById('calculation').innerHTML='Maximum Number of telephone stations exceeded';
	}
	else {
		document.getElementById('calculation').innerHTML=Math.ceil(u*h*d*52*e/1000) + ' GB Per Year For Storage';
	}
}