/* schema for linearArray is [ID, NAME, CONVERSION], position 0 is a blank entry for the dropdown menu.
  the conversion collumn is the number you would multiply it by in order to get a result in feet. */
  
  var conversionArray = new Array(	[0,"",0, 0],
									[1, "Inches", 12, 144],
  									[2, "Feet", 1, 1],
  									[3, "Yards", 1/3, 1/9],	
									[4, "Rods", 1/16.5, 1/272.25],
  									[5, "Chains", 1/66, 1/4356],
  									[6, "Acres", 0, 1/43560],
  									[7, "Miles", 1/5280, 1/27878400])
  
  /* for adding units to the array, just remember to update all the ID numbers so that they are in order of how they
  are endetered. i.e. if you place a unit in after the 3 put the next one in at 4 and increment the rest of the list */
  
  var arrayLength = 8 //IMPORTANT! change this when you add content to the areaArray, always 1 + the last ID number

  //ADT constants
  var ID = 0
  var NAME = 1
  var LINEAR = 2
  var AREA = 3



function convertArea(form)
  {
  	if(form.inputX.value != "" && form.inputY.value != "" && form.inputUnits.value != 0 && form.convertUnits.value != 0)
  		{  			
			var inputXFeet = form.inputX.value * (1 / conversionArray[form.inputUnits.value][LINEAR])
  			var inputYFeet = form.inputY.value * (1 / conversionArray[form.inputUnits.value][LINEAR])
  	 		form.output.value = (inputXFeet * conversionArray[form.convertUnits.value][LINEAR]
  	 							   * (inputYFeet * conversionArray[form.convertUnits.value][LINEAR]))
  	 		form.acres.value = (inputXFeet * inputYFeet) / 43560
  	 	}
  }
  
  
function convert(form)
  {
  	if(form.input.value != "" && form.inputUnits.value != 0 && form.convertUnits.value != 0)
  		{
  			var inputInFeet = form.input.value * (1 / conversionArray[form.inputUnits.value][AREA])
  	 		form.output.value = (inputInFeet * conversionArray[form.convertUnits.value][AREA])
  	 	}
  }
  
  
function convertLinear(form)
  {
  	if(form.input.value != "" && form.inputUnits.value != 0 && form.convertUnits.value != 0)
  		{  			
  			var inputInFeet = form.input.value * (1 / conversionArray[form.inputUnits.value][LINEAR])
  	 		form.output.value = inputInFeet * conversionArray[form.convertUnits.value][LINEAR]
  	 	}
  }