function area_left_to_right()
	{
	document.getElementById('areabox2').value = ( document.getElementById('areabox1').value / document.getElementById('areamenu1').value ) * document.getElementById('areamenu2').value;
	}
function area_right_to_left()
	{
	document.getElementById('areabox1').value = ( document.getElementById('areabox2').value / document.getElementById('areamenu2').value ) * document.getElementById('areamenu1').value;
	}


function length_left_to_right()
	{
	document.getElementById('lengthbox2').value = ( document.getElementById('lengthbox1').value / document.getElementById('lengthmenu2').value ) * document.getElementById('lengthmenu1').value;
	}
function length_right_to_left()
	{
	document.getElementById('lengthbox1').value = ( document.getElementById('lengthbox2').value / document.getElementById('lengthmenu1').value ) * document.getElementById('lengthmenu2').value;
	}


function weight_left_to_right()
	{
	document.getElementById('weightbox2').value = ( document.getElementById('weightbox1').value / document.getElementById('weightmenu2').value ) * document.getElementById('weightmenu1').value;
	}
function weight_right_to_left()
	{
	document.getElementById('weightbox1').value = ( document.getElementById('weightbox2').value / document.getElementById('weightmenu1').value ) * document.getElementById('weightmenu2').value;
	}


function speed_left_to_right()
	{
	document.getElementById('speedbox2').value = ( document.getElementById('speedbox1').value / document.getElementById('speedmenu2').value ) * document.getElementById('speedmenu1').value;
	}
function speed_right_to_left()
	{
	document.getElementById('speedbox1').value = ( document.getElementById('speedbox2').value / document.getElementById('speedmenu1').value ) * document.getElementById('speedmenu2').value;
	}


function energy_left_to_right()
	{
	document.getElementById('energybox2').value = ( document.getElementById('energybox1').value / document.getElementById('energymenu2').value ) * document.getElementById('energymenu1').value;
	}
function energy_right_to_left()
	{
	document.getElementById('energybox1').value = ( document.getElementById('energybox2').value / document.getElementById('energymenu1').value ) * document.getElementById('energymenu2').value;
	}


function power_left_to_right()
	{
	document.getElementById('powerbox2').value = ( document.getElementById('powerbox1').value / document.getElementById('powermenu2').value ) * document.getElementById('powermenu1').value;
	}
function power_right_to_left()
	{
	document.getElementById('powerbox1').value = ( document.getElementById('powerbox2').value / document.getElementById('powermenu1').value ) * document.getElementById('powermenu2').value;
	}


function volume_left_to_right()
	{
	document.getElementById('volumebox2').value = ( document.getElementById('volumebox1').value / document.getElementById('volumemenu2').value ) * document.getElementById('volumemenu1').value;
	}
function volume_right_to_left()
	{
	document.getElementById('volumebox1').value = ( document.getElementById('volumebox2').value / document.getElementById('volumemenu1').value ) * document.getElementById('volumemenu2').value;
	}


function time_left_to_right()
	{
	document.getElementById('timebox2').value = ( document.getElementById('timebox1').value / document.getElementById('timemenu2').value ) * document.getElementById('timemenu1').value;
	}
function time_right_to_left()
	{
	document.getElementById('timebox1').value = ( document.getElementById('timebox2').value / document.getElementById('timemenu1').value ) * document.getElementById('timemenu2').value;
	}


function pressure_left_to_right()
	{
	document.getElementById('pressurebox2').value = ( document.getElementById('pressurebox1').value / document.getElementById('pressuremenu1').value ) * document.getElementById('pressuremenu2').value;
	}
function pressure_right_to_left()
	{
	document.getElementById('pressurebox1').value = ( document.getElementById('pressurebox2').value / document.getElementById('pressuremenu2').value ) * document.getElementById('pressuremenu1').value;
	}


function temp_left_to_right()
	{
	switch (document.getElementById('tempmenu1').value + document.getElementById('tempmenu2').value)
		{
		case "cc": 
		document.getElementById('tempbox2').value = document.getElementById('tempbox1').value;
		break;
		case "ff": 
		document.getElementById('tempbox2').value = document.getElementById('tempbox1').value;
		break;
		case "kk": 
		document.getElementById('tempbox2').value = document.getElementById('tempbox1').value;
		break;
		
		case "cf": 
		document.getElementById('tempbox2').value = (1.8 * document.getElementById('tempbox1').value) + 32;
		break;
		case "ck": 
		document.getElementById('tempbox2').value = Number(document.getElementById('tempbox1').value) + 273.15;
		break;

		case "fc": 
		document.getElementById('tempbox2').value = (5/9) * (document.getElementById('tempbox1').value - 32);
		break;
		case "fk": 
		document.getElementById('tempbox2').value = ((5/9) * (document.getElementById('tempbox1').value - 32)) + 273.15;
		break;

		case "kc": 
		document.getElementById('tempbox2').value = Number(document.getElementById('tempbox1').value) - 273.15;
		break;
		case "kf": 
		document.getElementById('tempbox2').value = ( (9/5) * (document.getElementById('tempbox1').value - 273.15)) + 32;
		break;
		}
	}