diff --git a/mention.js b/mention.js
index 7c390ed..de3a8b7 100644
--- a/mention.js
+++ b/mention.js
@@ -35,18 +35,18 @@
                 },
                 _matcher = function(itemProps) {
                     var i;
-                    
+
                     if(settings.emptyQuery){
-	                    var q = (this.query.toLowerCase()),
-	                    	caratPos = this.$element[0].selectionStart,
-	                    	lastChar = q.slice(caratPos-1,caratPos);
-	                    if(lastChar==settings.delimiter){
-		                    return true;
-	                    }
+                        var q = (this.query.toLowerCase()),
+                            caratPos = this.$element[0].selectionStart,
+                            lastChar = q.slice(caratPos-1,caratPos);
+                        if(lastChar==settings.delimiter){
+                            return true;
+                        }
                     }
-                    
+
                     for (i in settings.queryBy) {
-                        if (itemProps[settings.queryBy[i]]) {
+                        if (itemProps[settings.queryBy[i]] && settings.queryBy.hasOwnProperty(i)) {
                             var item = itemProps[settings.queryBy[i]].toLowerCase(),
                                 usernames = (this.query.toLowerCase()).match(new RegExp(settings.delimiter + '\\w+', "g")),
                                 j;
@@ -68,17 +68,17 @@
                     var data = this.query,
                         caratPos = this.$element[0].selectionStart,
                         i;
-                    
+
                     for (i = caratPos; i >= 0; i--) {
                         if (data[i] == settings.delimiter) {
                             break;
                         }
                     }
                     var replace = data.substring(i, caratPos),
-                    	textBefore = data.substring(0, i),
-                    	textAfter = data.substring(caratPos),
-                    	data = textBefore + settings.delimiter + item + textAfter;
-                    	
+                        textBefore = data.substring(0, i),
+                        textAfter = data.substring(caratPos),
+                        data = textBefore + settings.delimiter + item + textAfter;
+
                     this.tempQuery = data;
 
                     return data;
@@ -111,9 +111,13 @@
                                 }
                             }
                             for (i in priorities) {
-                                var j;
-                                for (j in priorities[i]) {
-                                    finals.push(priorities[i][j]);
+                                if(priorities.hasOwnProperty(i)) {
+                                    var j;
+                                    for (j in priorities[i]) {
+                                        if(priorities[i].hasOwnProperty(j)) {
+                                            finals.push(priorities[i][j]);
+                                        }
+                                    }
                                 }
                             }
                             return finals;