filter js code for lamps

jQuery(document).ready(function( $ ) {
	
  var linetypes = new Array();
  var items = new Array();
  var subitems = new Array();
  $('.specs tr').each(function() {
    if(linetypes.indexOf($(this).data('linetype')) === -1){
      linetypes.push($(this).data('linetype'));
    }
    if(items.indexOf($(this).data('item')) === -1){
      items.push($(this).data('item'));
    }
    if(subitems.indexOf($(this).data('subitem')) === -1){
      subitems.push($(this).data('subitem'));
    }
  });
  
  var option = '<option value="">- SELECT -</option>';
  for (var i=0;i<linetypes.length;i++){
     option += '<option value="'+ linetypes[i] + '">' + linetypes[i] + '</option>';
  }
  
  $('select[name="linetype__select"]').append(option);
  
  var option = '<option value="">- SELECT -</option>';
  for (var i=0;i<items.length;i++){
     option += '<option value="'+ items[i] + '">' + items[i] + '</option>';
  }
  
  $('select[name="item__select"]').append(option);
  
  var option = '<option value="">- SELECT -</option>';
  for (var i=0;i<subitems.length;i++){
     option += '<option value="'+ subitems[i] + '">' + subitems[i] + '</option>';
  }
  
  $('select[name="subitem__select"]').append(option);
	
	linetype_val = false;
	item_val = false;
	subitem_val = false;
	
	$('.spec__search input[type="submit"]').click(function(){
		var linetype_val = $('select[name="linetype__select"]').val();
		var item_val = $('select[name="item__select"]').val();
		var subitem_val = $('select[name="subitem__select"]').val();
		if (linetype_val && item_val && subitem_val) {
			$('tr').hide()
			    .filter('[data-linetype="'+linetype_val+'"][data-item="'+item_val+'"][data-subitem="'+subitem_val+'"]')
			    .show();
		}
		if (!linetype_val && item_val && subitem_val) {
			$('tr').hide()
			    .filter('[data-item="'+item_val+'"][data-subitem="'+subitem_val+'"]')
			    .show();
		}
		if (!linetype_val && !item_val && subitem_val) {
			$('tr').hide()
			    .filter('[data-subitem="'+subitem_val+'"]')
			    .show();
		}
		if (!linetype_val && item_val && !subitem_val) {
			$('tr').hide()
			    .filter('[data-item="'+item_val+'"]')
			    .show();
		}
		if (linetype_val && item_val && !subitem_val) {
			$('tr').hide()
			    .filter('[data-linetype="'+linetype_val+'"][data-item="'+item_val+'"]')
			    .show();
		}
		
		if (linetype_val && !item_val && !subitem_val) {
			$('tr').hide()
			    .filter('[data-linetype="'+linetype_val+'"]')
			    .show();
		}

		
	});


	function filter(a, e){
	$('tr').hide()
	    .filter('[data-'+a+'="'+ e +'"]')
	    .show(); // show the filtered elements
	}
  
});