function llenaCboTo()
{
	var from = document.getElementById('from');
	var to = document.getElementById('to');
	var tipo = document.getElementById('tipo');
	var valuefrom = document.getElementById('valuefrom');
	
	while (to.length) to.remove(0);
	if (from.value==11)
	{		var selOpcion=new Option('Metros cúbicos', '12');eval(to.options[0]=selOpcion);}
	if (from.value==12)
	{		var selOpcion=new Option('Pie cúbico', '11');eval(to.options[0]=selOpcion);	}	

	if (from.value==21)
	{	var selOpcion=new Option('Kilogramos', '22');eval(to.options[0]=selOpcion);}
	if (from.value==22)
	{	var selOpcion=new Option('Libras', '21');eval(to.options[0]=selOpcion);	}

	//Length//
	if (from.value>=31 && from.value<=37) 
	{	
	var selOpcion=new Option('Centímetros', '31')	;eval(to.options[0]=selOpcion);
	var selOpcion=new Option('Pulgadas', '32')		;eval(to.options[1]=selOpcion);
	var selOpcion=new Option('Metros', '33')		;eval(to.options[2]=selOpcion);
	var selOpcion=new Option('Pie', '34')			;eval(to.options[3]=selOpcion);
	var selOpcion=new Option('Yardas', '35')			;eval(to.options[4]=selOpcion);
	var selOpcion=new Option('Millas náuticas', '36');eval(to.options[5]=selOpcion);
	var selOpcion=new Option('Kilómetros', '37')	;eval(to.options[6]=selOpcion);
	}

	if (from.value==41) //Acres//
	{		var selOpcion=new Option('Hectáreas', '42');eval(to.options[0]=selOpcion);}
	if (from.value==42) //Hectares//
	{		var selOpcion=new Option('Acres', '41');eval(to.options[0]=selOpcion);}

	if (from.value==51) //Gallons (USA)//
	{	
		var selOpcion=new Option('Litros', '52');eval(to.options[0]=selOpcion);
		var selOpcion=new Option('Galones (UK)', '53');eval(to.options[1]=selOpcion);
	}
	
	if (from.value==52) //Litres//
	{	
		var selOpcion=new Option('Galones (USA)', '51');eval(to.options[0]=selOpcion);
		var selOpcion=new Option('Galones (UK)', '53');eval(to.options[1]=selOpcion);
	}
	if (from.value==53) //Gallons (UK)//
	{
		var selOpcion=new Option('Galones (USA)', '51');eval(to.options[0]=selOpcion);
		var selOpcion=new Option('Litros', '52');eval(to.options[1]=selOpcion);
	}
	Calculo();
}

function llenaCboFrom()
{
	var from = document.getElementById('from');
	var to = document.getElementById('to');
	var tipo = document.getElementById('tipo');
	var valuefrom = document.getElementById('valuefrom');
	
	while (from.length) from.remove(0);
	while (to.length) to.remove(0);

	if (tipo.value==1)
	{
	var selOpcion=new Option('Pie cúbico', '11');eval(from.options[0]=selOpcion);
	var selOpcion=new Option('Metros cúbicos', '12');eval(from.options[1]=selOpcion);
	}

	if (tipo.value==2)
	{
	var selOpcion=new Option('Libras', '21');eval(from.options[0]=selOpcion);
	var selOpcion=new Option('Kilogramos', '22');eval(from.options[1]=selOpcion);
	}

	if (tipo.value==3)
	{
	var selOpcion=new Option('Centímetros', '31')	;eval(from.options[0]=selOpcion);
	var selOpcion=new Option('Pulgadas', '32')		;eval(from.options[1]=selOpcion);
	var selOpcion=new Option('Metros', '33')		;eval(from.options[2]=selOpcion);
	var selOpcion=new Option('Pie', '34')			;eval(from.options[3]=selOpcion);
	var selOpcion=new Option('Yardas', '35')			;eval(from.options[4]=selOpcion);
	var selOpcion=new Option('Millas náuticas', '36');eval(from.options[5]=selOpcion);
	var selOpcion=new Option('Kilómetros', '37')	;eval(from.options[6]=selOpcion);
	}

	if (tipo.value==4)
	{
	var selOpcion=new Option('Acres', '41');eval(from.options[0]=selOpcion);var selOpcion=new Option('Hectáreas', '42');eval(from.options[1]=selOpcion);
	}
	
	if (tipo.value==5)
	{
	var selOpcion=new Option('Galones (USA)', '51');	eval(from.options[0]=selOpcion);	var selOpcion=new Option('Litros', '52');	eval(from.options[1]=selOpcion);	var selOpcion=new Option('Galones (UK)', '53');	eval(from.options[2]=selOpcion);
	}
	llenaCboTo();	
}

function Calculo()
{
	var from = document.getElementById('from');
	var to = document.getElementById('to');
	var result = document.getElementById('result');
	var valuefrom = document.getElementById('valuefrom');
	var result = document.getElementById('result');
	
	result.value=valuefrom.value;
	
	// Capacity// 
	if (from.value==11 && to.value==12)
	{result.value=valuefrom.value*0.028317;}
	else
	{if (from.value==12 && to.value==11){result.value=valuefrom.value*35.3145;}}

	//Weight//
	if (from.value==21 && to.value==22)
	{result.value=valuefrom.value*0.4536;}
	else
	{if (from.value==22 && to.value==21){result.value=valuefrom.value*2.2046;}}

	//Length - Centimetres//
	if (from.value==31 && to.value==31) //to centimeters//
	{result.value=valuefrom.value*1;}	
	if (from.value==31 && to.value==32) //to inches//
	{result.value=valuefrom.value*0.3937;}	
	if (from.value==31 && to.value==33) //to metres//
	{result.value=valuefrom.value*0.01;}
	if (from.value==31 && to.value==34) //to feet//
	{result.value=valuefrom.value*0.03281;}
	if (from.value==31 && to.value==35) //to yards//
	{result.value=valuefrom.value*0.01094;}
	if (from.value==31 && to.value==36) //to Nautical miles//
	{result.value=valuefrom.value*0.0000054;}
	if (from.value==31 && to.value==37) //to Kilometers//
	{result.value=valuefrom.value*0.00001;}	

	//Length - Inches//					
	if (from.value==32 && to.value==31)
	{result.value=valuefrom.value*2.54;} //to centimeters//
	if (from.value==32 && to.value==32)
	{result.value=valuefrom.value*1;} //to inches//
	if (from.value==32 && to.value==33)
	{result.value=valuefrom.value*0.0254;} //to meters//
	if (from.value==32 && to.value==34)
	{result.value=valuefrom.value*0.08333;} //to feet//
	if (from.value==32 && to.value==35)
	{result.value=valuefrom.value*0.02778;} //to yards//
	if (from.value==32 && to.value==36)
	{result.value=valuefrom.value*0.00001371;} //to Nautical miles//
	if (from.value==32 && to.value==37)
	{result.value=valuefrom.value*0.0000254;} //to Kilometers//
	
	//Length - Metres//
	if (from.value==33 && to.value==31)	//to centimetres//
	{result.value=valuefrom.value*100;}
	if (from.value==33 && to.value==32)	//to inches//
	{result.value=valuefrom.value*39.37;} 
	if (from.value==33 && to.value==33)	//to metres//
	{result.value=valuefrom.value*1;}
	if (from.value==33 && to.value==34) //to feet//
	{result.value=valuefrom.value*3.2010;}	
	if (from.value==33 && to.value==35) //to yards//
	{result.value=valuefrom.value*1.094;}
	if (from.value==33 && to.value==36) //to Nautical Miles//
	{result.value=valuefrom.value*0.00054;}
	if (from.value==33 && to.value==37) //to Kilometres//
	{result.value=valuefrom.value*0.001;}	

	//Length - Feet//
	if (from.value==34 && to.value==31)	//to centimetres//
	{result.value=valuefrom.value*30.48;}	
	if (from.value==34 && to.value==32)	//to inches//
	{result.value=valuefrom.value*12;}
	if (from.value==34 && to.value==33)	//to meters//
	{result.value=valuefrom.value*0.3048;}	
	if (from.value==34 && to.value==34)	//to feet//
	{result.value=valuefrom.value*1;}
	if (from.value==34 && to.value==35)	//to yards//
	{result.value=valuefrom.value*0.3333;}
	if (from.value==34 && to.value==36)	//to Nautical Miles//
	{result.value=valuefrom.value*0.0001646;}
	if (from.value==34 && to.value==37)	//to Kilometres//
	{result.value=valuefrom.value*0.0003048;}
	
	//Length - Yards//	
	if (from.value==35 && to.value==31)	//to centimetres//
	{result.value=valuefrom.value*91.44;}	
	if (from.value==35 && to.value==32)	//to inches//
	{result.value=valuefrom.value*36;}
	if (from.value==35 && to.value==33)	//to meters//
	{result.value=valuefrom.value*0.9144;}	
	if (from.value==35 && to.value==34)	//to feet//
	{result.value=valuefrom.value*3;}
	if (from.value==35 && to.value==35)	//to yards//
	{result.value=valuefrom.value*1;}
	if (from.value==35 && to.value==36)	//to Nautical Miles//
	{result.value=valuefrom.value*0.0004937;}
	if (from.value==35 && to.value==37)	//to Kilometres//
	{result.value=valuefrom.value*0.0009144;}

	//Length - Nautical Miles//	
	if (from.value==36 && to.value==31)	//to centimetres//
	{result.value=valuefrom.value*185200;}	
	if (from.value==36 && to.value==32)	//to inches//
	{result.value=valuefrom.value*72910;}
	if (from.value==36 && to.value==33)	//to meters//
	{result.value=valuefrom.value*1852;}	
	if (from.value==36 && to.value==34)	//to feet//
	{result.value=valuefrom.value*6076;}
	if (from.value==36 && to.value==35)	//to yards//
	{result.value=valuefrom.value*2025;}
	if (from.value==36 && to.value==36)	//to Nautical Miles//
	{result.value=valuefrom.value*1;}
	if (from.value==36 && to.value==37)	//to Kilometres//
	{result.value=valuefrom.value*1.852;}

	//Length - Kilometres//	
	if (from.value==37 && to.value==31)	//to centimetres//
	{result.value=valuefrom.value*100000;}	
	if (from.value==37 && to.value==32)	//to inches//
	{result.value=valuefrom.value*39370;}
	if (from.value==37 && to.value==33)	//to meters//
	{result.value=valuefrom.value*1000;}	
	if (from.value==37 && to.value==34)	//to feet//
	{result.value=valuefrom.value*3281;}
	if (from.value==37 && to.value==35)	//to yards//
	{result.value=valuefrom.value*1094;}
	if (from.value==37 && to.value==36)	//to Nautical Miles//
	{result.value=valuefrom.value*0.5400;}
	if (from.value==37 && to.value==37)	//to Kilometres//
	{result.value=valuefrom.value*1;}
	

	//Area//
	if (from.value==41 && to.value==42)	//Acres to Hectares//
	{result.value=valuefrom.value*0.0405;}	
	if (from.value==42 && to.value==41)	//Hectares to Acres//
	{result.value=valuefrom.value*2.4710;}	

	//Fuel//
	if (from.value==51 && to.value==52)	//G USA to Litres//
	{result.value=valuefrom.value*3.7853;}	
	if (from.value==51 && to.value==53)	//G USA to G UK//
	{result.value=valuefrom.value*1.201;}
	if (from.value==53 && to.value==52)	//G UK to Litres//
	{result.value=valuefrom.value*4.5460;}
	if (from.value==53 && to.value==51)	//G UK to G USA//
	{result.value=valuefrom.value*0.8327;}	
	if (from.value==52 && to.value==51)	//Litres to G USA//
	{result.value=valuefrom.value*0.2642;}	
	if (from.value==52 && to.value==53)	//Litres to G UK//
	{result.value=valuefrom.value*0.220;}
}