diff --git a/parse.scm b/parse.scm
index 6bfbf68..02f1668 100644
--- a/parse.scm
+++ b/parse.scm
@@ -36,17 +36,17 @@
 ;; Predicates
 
 (define contains-ingredient?
-  (lambda (recipe search-ingredient)
-    (contains-ingredients? recipe (cons search-ingredient '()))))
+  (lambda (search-ingredient recipe)
+    (contains-ingredients? (list search-ingredient) recipe)))
 
 (define contains-ingredients?
-  (lambda (recipe search-ingredients)
+  (lambda (search-ingredients recipe)
     (let ((ingredients (recipe-ingredients recipe)))
       (cond [(null? search-ingredients) #t]
-            [(ingredient-by-name ingredients
-                                 (car search-ingredients))
-             (contains-ingredients? recipe
-                                    (cdr search-ingredients))]
+            [(ingredient-by-name (car search-ingredients)
+                                 ingredients)
+             (contains-ingredients? (cdr search-ingredients)
+                                    recipe)]
             [else #f])
       )))
 
@@ -63,18 +63,18 @@
         (ingredient-ref (cdr ingredients) (- n 1)))))
 
 (define ingredient-by-name
-  (lambda (ingredients search-name)
-    (let ((ingredient (car ingredients)))
+  (lambda (search-name ingredient-list)
+    (let ((ingredient (car ingredient-list)))
       (cond [(equal? (ingredient-name ingredient)
                      search-name)
              ingredient]
-            [(null? (cdr ingredients)) #f]
-            [else (ingredient-by-name (cdr ingredients)
-                                      search-name)]))))
+            [(null? (cdr ingredient-list)) #f]
+            [else (ingredient-by-name search-name
+                                      (cdr ingredient-list))]))))
 
 (define recipes-by-ingredients
-  (lambda (recipes search-ingredients)
-    (filter (lambda (x) (contains-ingredients? x search-ingredients))
+  (lambda (search-ingredients recipes)
+    (filter (lambda (x) (contains-ingredients? search-ingredients x))
             recipes)))
 
 (define recipe-by-name
@@ -89,15 +89,15 @@
 
 ;; Manipulation
 
-(define scale-recipe
-  (lambda (recipe wanted-servings)
+(define scale-recipe-by-servings
+  (lambda (wanted-servings recipe)
     (let ([name (recipe-name recipe)]
           [ingredients (recipe-ingredients recipe)]
           [steps (recipe-steps recipe)]
           [servings (recipe-servings recipe)])
       (let ([new-name name]
             [new-ingredients (map (lambda (ingr)
-                                    (list (* (/ (car ingr)
+                                    (cons (* (/ (car ingr)
                                                 servings)
                                              wanted-servings)
                                           (cdr ingr)))
@@ -108,9 +108,9 @@
         ))))
 
 (define scale-recipe-by-factor
-  (lambda (recipe scale-factor)
+  (lambda (scale-factor recipe)
     (let ([new-servings (* (recipe-servings recipe) scale-factor)])
-      (scale-recipe recipe new-servings))))
+      (scale-recipe-by-servings new-servings recipe))))
 
 ;; Constructors
 
diff --git a/web/server.rb b/web/server.rb
index 032592a..07c64cb 100644
--- a/web/server.rb
+++ b/web/server.rb
@@ -3,15 +3,26 @@ require 'sinatra'
 require 'htmlentities'
 
 get '/' do
+  servings = params['servings']
+  scaling_factor = params['scale']
   `cd ..; echo "(display (html-wrap (cookbook-as-html cookbook)))" | petite -q "batch.scm"`
 end
 
 get '/ingredient/:ingredient' do
   ingredient = HTMLEntities.new.decode params['ingredient']
-  `cd ..; echo "(display (html-wrap (cookbook-as-html (recipes-by-ingredients cookbook '(\\"#{ingredient}\\")))))" | petite -q "batch.scm"`
+  `cd ..; echo "(display (html-wrap (cookbook-as-html (recipes-by-ingredients '(\\"#{ingredient}\\" cookbook)))))" | petite -q "batch.scm"`
 end
 
 get '/recipe/:title' do
   title = HTMLEntities.new.decode params['title']
-  `cd ..; echo "(display (html-wrap (recipe-as-html (recipe-by-name cookbook \\"#{title}\\"))))" | petite -q "batch.scm"`
+  servings = params['servings']
+  scaling_factor = params['scale']
+  if servings
+    puts "servings"
+    `cd ..; echo "(display (html-wrap (recipe-as-html (scale-recipe-by-servings #{servings} (recipe-by-name \\"#{title}\\" cookbook)))))" | petite -q "batch.scm"`
+  elsif scaling_factor
+    `cd ..; echo "(display (html-wrap (recipe-as-html (scale-recipe-by-factor #{scaling_factor} (recipe-by-name \\"#{title}\\" cookbook)))))" | petite -q "batch.scm"`
+  else
+    `cd ..; echo "(display (html-wrap (recipe-as-html (recipe-by-name \\"#{title}\\" cookbook))))" | petite -q "batch.scm"`
+  end
 end