function reset_form(){
  $('mpg').value = '';
  $('miles').value = '12000';
  $('fuel_gasoline').checked = true;

  $('gallons').innerHTML = '0';
  $('pounds').innerHTML = '0';
  $('pri').innerHTML = '0';
  $('vehicle').innerHTML = " Emissions Calculator ";
  //$('tier').innerHTML = "----";

  $('vm_year').selected = true;

  $('select_vehicle_model').innerHTML = "<span class=\"labelcell\">Model:</span> <select><option>---</option></select></div>";
  $('select_vehicle_make').innerHTML = "<span class=\"labelcell\">Make:</span> <select><option>---</option></select>";
  $('select_vehicle_complete').innerHTML = "";

  $('confirm1').checked = false;
  $('confirm1').disabled = true;
  $('add_to_cart').disabled = true;

  $('vehicle_model_id').value = '';
  $('tons').value = '';
  $('price').value = '';
  $('product').value = '';

}

function func_confirm() {
  if ($('confirm1').checked) {
    $('add_to_cart').disabled = false;


  } else {
    $('add_to_cart').disabled = true;
  }
}

//////////////////////////////////
function calculateMpg(pricePerTon){
  if (!($('miles').value && $('mpg').value)) {
    alert ("'Miles per gallon' and 'Annual miles Driven should not blank'");
    return;
  }

  $('miles').value = $('miles').value.replace(/,/g, '');
  $('miles').value = $('miles').value.split(',').join();

  var x = Number($('miles').value)/Number($('mpg').value);
  x = parseInt(x);
  var y=" ";
  var d1 = document.getElementById("gallons");
  var d2 = document.getElementById("pounds");
  var d3 = document.getElementById("pri");
  var i;

  if($('fuel_gasoline').checked == true){
    y=x; i=0;
  } else if($('fuel_diesel').checked == true){
    y=(x * 1.15); i=1;
  }else if(  $('fuel_cng').checked == true){
    y=(x * 0.77);i=2;
  }else if(  $('fuel_biodiesel').checked == true){
    y=(x * 0.25);i=3;
  }

  y=parseInt(y);
  d1.innerHTML=' '+y+' ';
  var z=y*19.4;
  z=parseInt(z);
  var t;
  var tons;
  var pp=0;
  tons=z/2205;
      tons = Math.ceil(parseFloat(tons*2))/2;

  if (tons <= 1){
    tons = 1
	} else tons=(Math.round(tons*10))/10

  pp = tons * pricePerTon;

  d3.innerHTML=pp.toFixed(2);
  d2.innerHTML=' '+z+' ';

  $('price').value = pp;
  $('tons').value = tons;
  $('confirm1').disabled = false;
}