/* 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]
                   }
  }