Added new parents, parent and siblings functions.

Siblings function still needs some work.
It would be nice to have an optional -or-self argument too.

jquery/jquery.js

@@ -214,17 +214,23 @@ function $(a,c) {
 		},
 
     parent: function(a) {
-			if ( a == null ) a = 1;
       this.cur = $.map(this.cur,function(d){
-				var b = $.parents(d);
-				if ( a == 0 )
-					return b;
-				else if ( a.constructor == String ) {
-					var c = $.filter(a,b);
-					return c.length > 0 ? c[0] : null;
-				} else
-					return b.length >= a ? b[a-1] : null;
+        return d.parentNode;
       });
+      if ( a ) this.cur = $.filter(a,this.cur).r;
+      return this;
+    },
+
+    parents: function(a) {
+      this.cur = $.map(this.cur,$.parents);
+      if ( a ) this.cur = $.filter(a,this.cur).r;
+      return this;
+    },
+
+    siblings: function(a) {
+      // Incorrect, need to exclude current element
+      this.cur = $.map(this.cur,$.sibling);
+      if ( a ) this.cur = $.filter(a,this.cur).r;
       return this;
     },
 		
@@ -573,7 +579,7 @@ $.filter = function(t,r,not) {
 $.parents = function(a){
 	var b = [];
 	var c = a.parentNode;
-	while ( c != null && c != c.documentElement ) {
+	while ( c != null && c != document ) {
 		b[b.length] = c;
 		c = c.parentNode;
 	}