function selectGift(value) {
	switch(value) {
		case "amount":
			document.getElementById('giftAmount').disabled = false;
			document.getElementById('giftTons').disabled = true;
			document.getElementById('giftTrees').disabled = true;
			break;
		case "tons":
			document.getElementById('giftAmount').disabled = true;
			document.getElementById('giftTons').disabled = false;
			document.getElementById('giftTrees').disabled = true;
			break;
		case "trees":
			document.getElementById('giftAmount').disabled = true;
			document.getElementById('giftTons').disabled = true;
			document.getElementById('giftTrees').disabled = false;
			break;
	}
}

function calculateTons() {
	var cost = document.getElementById('costTextbox').value;

	if(cost == "") {
		cost = 0;
	}
	
	document.getElementById('tonsTextbox').value = parseFloat(cost) / 120.0;
	
}

function calculateCost() {
	var cost = document.getElementById('tonsTextbox').value;

	if(cost == "") {
		cost = 0;
	}
	
	document.getElementById('costTextbox').value = formatCurrency(parseFloat(cost) * 120.0);
	
}

$(document).ready(function(){
	$(".validation_integer").each(
		function( intIndex ) {
			$(this).keypress(function (e) {
				if( e.which!=8 && e.which!=0 && (e.which<48 || e.which>57) &&  e.which != 44 &&  e.which != 46)
				{
					return false;
				}
			});
		}
	);
});

/*
// override the native javascript alert function
window['alert'] = function alert(message) {
	nvi.panelManager.getInstance( "modal" ).open();
	NVI('#alertMessage').html(message);
}
*/