var data1 = new Array(1, 0.1, 0.001, 0.000001, 10/16093440, 10/254, 10/3048, 10/9144, 0.001/1852, (10/16093440)/3, 0.001/5556, (10/3048)/6);
var data2 = new Array(10, 1, 0.01, 0.00001, 100/16093440, 100/254, 100/3048, 100/9144, 0.01/1852, (100/16093440)/3, 0.01/5556, (100/3048)/6);
var data3 = new Array(1000, 100, 1, 0.001, 10000/16093440, 10000/254, 10000/3048, 10000/9144, 1/1852, (10000/16093440)/3, 1/5556, (10000/3048)/6);
var data4 = new Array(1000000, 100000, 1000, 1, 10000000/16093440, 10000000/254, 10000000/3048, 10000000/9144, 1000/1852, (10000000/16093440)/3, 1000/5556, (10000000/3048)/6);
var data5 = new Array(1609344, 160934.4, 1609.344, 1.609344, 1, 63360, 5280, 1760, 1/1.15077945, 1/3, (1/1.15077945)/3, 880);
var data6 = new Array(25.4, 2.54, 0.0254, 0.0000254, 0.0000158, 1, 0.08333, 0.02778, 0.0000137, 5.260943e-06, 4.57164e-06, 1/72);
var data7 = new Array(304.8, 30.48, 0.3048, 0.0003048, 0.0001896, 12, 1, 1/3, 0.0001646, 6.313131e-05, 5.485961e-05, 1/6);
var data8 = new Array(914.4, 91.44, 0.9144, 0.0009144, 0.0005688, 36, 3, 1, 0.0004937, 0.0001893939, 0.0001645788, 0.5);
var data9 = new Array(1852000, 185200, 1852, 1.852, 1.15077945, 72913.358268, 6076.11549, 2025.3718258, 1, 0.3835932, 1/3, 1012.686); 
var data10 = new Array(4828032, 482803.2, 4828.032, 4.828032, 3, 190080, 15840, 5280, 2.606929, 1, 0.8689762, 2640);
var data11 = new Array(5556000, 555600, 5556, 5.556, 3.452338, 218740.2, 18228.35, 6076.116, 3, 1.150779, 1, 3038.058);
var data12 = new Array(1828.8, 182.88, 1.8288, 0.0018288, 1/880, 72, 6, 2, 1/(880*1.15077945), (1/880)/3, (1/(880*1.15077945))/3, 1);
var factors = new Array(data1,data2,data3,data4,data5,data6,data7,data8,data9,data10,data11,data12);

function conversion_unit()
{
	digits = document.conversion.dec_digits.selectedIndex;
	document.getElementById("decimals").innerHTML = "Rounded to " + digits + " decimals";
      rounded = Math.pow(10,digits)
      from_index = document.conversion.from_unit.selectedIndex;
	to_index = document.conversion.to_unit.selectedIndex;
	factor = factors[from_index][to_index];
	document.getElementById("formula").innerHTML = " 1 " + document.conversion.from_unit.options[document.conversion.from_unit.selectedIndex].text + " = " + Math.round(factor*rounded)/rounded + " " + document.conversion.to_unit.options[document.conversion.to_unit.selectedIndex].text;
	if(isNaN(document.conversion.from_value.value))
		document.getElementById("to_value").innerHTML = "Not a valid number.";
	else
		document.getElementById("to_value").innerHTML = " = " + Math.round((factor * document.conversion.from_value.value)*rounded)/rounded;
}