function setMaterialOptions(chosen) {
var selbox = document.myform.material;
 
selbox.options.length = 0;
if (chosen == "") {
  selbox.options[selbox.options.length] = new Option('Select material','');
 
}
if (chosen == "12") {
  selbox.options[selbox.options.length] = new Option ('Select material', '');
  selbox.options[selbox.options.length] = new Option('Polypropylene','polypropylene');
  selbox.options[selbox.options.length] = new Option('ABS','ABS');
  selbox.options[selbox.options.length] = new Option('PVC','PVC');
}
if (chosen == "17") {
  selbox.options[selbox.options.length] = new Option ('Select material', '');
  selbox.options[selbox.options.length] = new Option('Polypropylene','polypropylene');
  selbox.options[selbox.options.length] = new Option('ABS','ABS');
  selbox.options[selbox.options.length] = new Option('PVC','PVC');
  selbox.options[selbox.options.length] = new Option('Brass','BRASS');
}
if (chosen == "25") {
  selbox.options[selbox.options.length] = new Option ('Select material', '');
  selbox.options[selbox.options.length] = new Option('Polypropylene','polypropylene');
  selbox.options[selbox.options.length] = new Option('ABS','ABS');
  selbox.options[selbox.options.length] = new Option('PVC','PVC');
}
if (chosen == "30") {
  selbox.options[selbox.options.length] = new Option ('Select material', '');
  selbox.options[selbox.options.length] = new Option('Polypropylene','polypropylene');
  selbox.options[selbox.options.length] = new Option('ABS','ABS');
  selbox.options[selbox.options.length] = new Option('PVC','PVC');
}
}

function setSizeOptions(chosen) {
var selbox = document.myform.size;
 
selbox.options.length = 0;
if (chosen == "") {
  selbox.options[selbox.options.length] = new Option('Select size','');
 
}
if (chosen == "polypropylene") {
  selbox.options[selbox.options.length] = new Option('Tub Depth 17" - 24"','17');
  selbox.options[selbox.options.length] = new Option('Tub Depth 25" - 29"','25');
}
if (chosen == "ABS") {
  selbox.options[selbox.options.length] = new Option('Tub Depth 12" - 16"','12');
  selbox.options[selbox.options.length] = new Option('Tub Depth 17" - 24"','17');
  selbox.options[selbox.options.length] = new Option('Tub Depth 25" - 29"','25');
  selbox.options[selbox.options.length] = new Option('Tub Depth 30"','30');
}
if (chosen == "PVC") {
  selbox.options[selbox.options.length] = new Option('Tub Depth 12" - 16"','12');
  selbox.options[selbox.options.length] = new Option('Tub Depth 17" - 24"','17');
  selbox.options[selbox.options.length] = new Option('Tub Depth 25" - 29"','25');
  selbox.options[selbox.options.length] = new Option('Tub Depth 30"','30');
}
if (chosen == "BRASS") {
  selbox.options[selbox.options.length] = new Option ('Select size', '');
  selbox.options[selbox.options.length] = new Option('Tub Depth 17" - 24"','17');
}
}