////////////////////////////////////////////////
//
//	Javascript code for conversion forms
//	------------------------------------
//
//	Weight based on:
//
//	1kg = 2.204624 lbs
//	1kg = 1000ml
//	1lb = 16oz
//
//	Volume based on:
//
//	1litre = 1.7598 pints
//	1litre - 1000ml
//	1 pint = 20 fl. oz.
//
////////////////////////////////////////////////



function weight() {
	if (document.getElementById('weightToMetric').checked) convert('pounds','ounces',16,'kilograms','grams',1000,0.453592);
	else if (document.getElementById('weightToImperial').checked) convert('kilograms','grams',1000,'pounds','ounces',16,2.204624);
	else alert("Select a conversion")
}

function volume() {
	if (document.getElementById('volToMetric').checked) convert('pint','fluidOunces',20,'litre','millilitres',1000,0.568246);
	else if (document.getElementById('volToImperial').checked) convert('litre','millilitres',1000,'pint','fluidOunces',20,1.7598);
	else alert("Select a conversion")
}

function convert(from1,from2,childRate1,to1,to2,childRate2,convertRate) {
	val1 = document.getElementById(from1).value;
	val2 = document.getElementById(from2).value
	if ((val1 == '') && (val2 == '')) {
		alert("Enter values to convert")
		return false;
	}
	else if (((val1 != '') && (typeof parseInt(val1) == 'NaN')) || ((val2 != '') && (typeof parseInt(val2) == 'NaN'))) {
		alert("Use numbers only!")
		return false;
	}
	
	if(document.getElementById(from1).value == '') {
		document.getElementById(from1).value = '0';
	}
	
	total = (parseInt(document.getElementById(from1).value) + parseFloat(document.getElementById(from2).value/childRate1)) * convertRate;
	if (total > 0) {
		document.getElementById(to1).value = parseInt(total);
		document.getElementById(to2).value = parseInt((total - parseInt(total))*childRate2);
	}
	else {
		alert("Ensure you only use numbers in this form");
	}
}