diff --git a/core.php b/core.php
index 7bc2a0b..e6a6c40 100644
--- a/core.php
+++ b/core.php
@@ -7,12 +7,15 @@ function request( $request ) {
 		if ( !isset( $_GET['qmt'] ) )
 			return $request;
 
+		$operator = strtoupper( $_GET['qmt_operator'] );
+		
 		foreach ( $_GET['qmt'] as $taxonomy => $terms ) {
+			
 			$request['tax_query'][] = array(
 				'taxonomy' => $taxonomy,
 				'terms' => $terms,
 				'field' => 'term_id',
-				'operator' => 'IN'
+				'operator' => $operator
 			);
 		}
 
@@ -226,11 +229,11 @@ function is_multitax( $taxonomies = array() ) {
  *
  * @return array( taxonomy => query )
  */
-function qmt_get_query( $taxname = '' ) {
+function qmt_get_query( $taxname = '', $glue = '+' ) {
 	global $wp_query;
 
 	$qmt_query = array();
-
+	
 	if ( !is_null( $wp_query->tax_query ) ) {
 		foreach ( $wp_query->tax_query->queries as &$tax_query ) {
 			$terms = _qmt_get_term_slugs( $tax_query );
@@ -243,7 +246,7 @@ function qmt_get_query( $taxname = '' ) {
 		}
 
 		foreach ( $qmt_query as &$value )
-			$value = implode( '+', $value );
+			$value = implode( $glue, $value );
 	}
 
 	if ( $taxname ) {
diff --git a/templates/checkboxes.html b/templates/checkboxes.html
index f544f4d..85c00ae 100644
--- a/templates/checkboxes.html
+++ b/templates/checkboxes.html
@@ -1,5 +1,6 @@
 <form method="get" action="{{base-url}}" class="taxonomy-drilldown-checkboxes">
-	{{#taxonomy}}
+	<input type="hidden" name="qmt_operator" value="{{operator}}"  />
+	{{#taxonomy}} 
 	<div id="terms-{{taxonomy}}">
 		<h4>{{title}}</h4>
 		<ul>
diff --git a/templates/lists.html b/templates/lists.html
index 04a079d..59aa6f7 100644
--- a/templates/lists.html
+++ b/templates/lists.html
@@ -1,4 +1,4 @@
-<div class="taxonomy-drilldown-lists">
+<div class="taxonomy-drilldown-lists"> 
 	{{#taxonomy}}
 	<div id="terms-{{taxonomy}}">
 		<h4>
diff --git a/walkers.php b/walkers.php
index b09b721..86c61d3 100644
--- a/walkers.php
+++ b/walkers.php
@@ -169,7 +169,11 @@ function specific_data( $term, $depth ) {
 class QMT_Checkboxes_Walker extends QMT_Walker {
 
 	protected function set_selected_terms() {
-		$this->selected_terms = explode( ',', qmt_get_query( $this->taxonomy ) );
+		
+		$terms = qmt_get_query( $this->taxonomy, ',');
+		 
+		$this->selected_terms = explode( ',', $terms );
+		
 	}
 
 	function specific_data( $term, $depth ) {
diff --git a/widget.html b/widget.html
index 4e44864..94cccc9 100644
--- a/widget.html
+++ b/widget.html
@@ -1,7 +1,12 @@
+
+
 <p>{{{title-input}}}</p>
 
 <p>{{{mode-input}}}</p>
 
+<p>{{{operator-input}}}</p>
+
+
 <p>{{{taxonomies-label}}}</p>
 
 <ul class="qmt-taxonomies">
diff --git a/widget.php b/widget.php
index 1a51c40..6529774 100644
--- a/widget.php
+++ b/widget.php
@@ -6,6 +6,7 @@ class Taxonomy_Drill_Down_Widget extends scbWidget {
 		'title' => '',
 		'mode' => 'lists',
 		'taxonomies' => array(),
+		'operator' => ''
 	);
 
 	static function init( $file ) {
@@ -51,6 +52,17 @@ function add_script() {
 		$(this).sortable();
 		$(this).disableSelection();
 	});
+	
+	$('#qmt_types').change(function(){
+		console.log($('#qmt_types').val());
+		if ( $('#qmt_types').val() != 'checkboxes' ) 
+			$('.operator').parent().hide();
+		else{
+			$('.operator').parent().show();
+		}
+
+	});
+		
 });
 </script>
 <?php
@@ -65,7 +77,7 @@ function form( $instance ) {
 				'name'  => 'title',
 				'type'  => 'text',
 				'desc' => __( 'Title:', 'query-multiple-taxonomies' ),
-				'extra' => array( 'class' => 'widefat' )
+				'extra' => array( 'class' => 'widefat', 'id'=>'prueba' )
 			), $instance ),
 
 			'mode-input' => $this->input( array(
@@ -78,12 +90,24 @@ function form( $instance ) {
 				),
 				'text'   => false,
 				'desc'   => __( 'Mode:', 'query-multiple-taxonomies' ),
-				'extra' => array( 'class' => 'widefat' )
+				'extra' => array( 'class' => 'widefat types', 'id'=>'qmt_types' )
+			), $instance ),
+			'operator-input' => $this->input( array(
+				'type'   => 'select',
+				'name'   => 'operator',
+				'values' => array(
+					'AND' =>  __( 'And', 'query-multiple-taxonomies' ),
+					'IN' => __( 'Or', 'query-multiple-taxonomies' )
+				),
+				'text'   => false,
+				'desc'   => __( 'Operator between terms:', 'query-multiple-taxonomies' ),
+				'extra' => array( 'class' => 'widefat operator' )
 			), $instance ),
 
 			'taxonomies-label' => __( 'Taxonomies:', 'query-multiple-taxonomies' )
 		);
 
+
 		$selected_taxonomies = $instance['taxonomies'];
 
 		// Start with the selected taxonomies
@@ -119,7 +143,7 @@ function form( $instance ) {
 
 	function content( $instance ) {
 		extract( $instance );
-
+ 
 		$taxonomies = array_filter( $taxonomies, array( __CLASS__, 'test_tax' ) );
 
 		$query = qmt_get_query();
@@ -133,6 +157,7 @@ function content( $instance ) {
 			echo call_user_func( array( __CLASS__, "generate_$mode" ), $taxonomies, array(
 				'reset-text' => __( 'Reset', 'query-multiple-taxonomies' ),
 				'reset-url' => QMT_URL::get(),
+				'operator'=>$operator
 			) );
 		}
 	}
@@ -204,6 +229,7 @@ private function generate_dropdowns( $taxonomies, $data ) {
 	}
 
 	private function generate_checkboxes( $taxonomies, $data ) {
+		
 		$data = array_merge( $data, array(
 			'base-url' => QMT_URL::get_base(),
 			'submit-text' => __( 'Submit', 'query-multiple-taxonomies' ),