function roundNumber(rnum, rlength) { // Arguments: number to round, number of decimal places
  var newnumber = Math.round(rnum*Math.pow(10,rlength))/Math.pow(10,rlength);
  return newnumber; // Output the result to the form field (change for your purposes)
}

function toggleUnits(newUnit, convertButtonID) {
	
	convertUnits(newUnit, convertButtonID);
	
}

/*
 * TODO - When clicking IS or ZS, change highlighting
 */
function convertUnits(newUnit, fieldID) {
	var valueField = document.getElementById(fieldID);
	var value = valueField.value;
	
	
	
	var mmToIn = .0393700787;
	var inToMM = 1.0/mmToIn;
	if (newUnit == 'mm') {
		mmVal = roundNumber(value*inToMM,2);
		valueField.value = mmVal;
		
	} else if (newUnit == 'in') {
		inVal = roundNumber(value*mmToIn,3);
		valueField.value = inVal;
	}
	
	
	
	
}