Change LookUp() to Lookup(). Spelling.

en/07.4.md

@@ -379,7 +379,7 @@ func main() {
 ```
 Here we can see that `template.ParseFiles` parses all nested templates into cache, and that every template defined by `{{define}}` are independent of each other. They are persisted in something like a map, where the template names are keys and the values are the template bodies. We can then use `ExecuteTemplate` to execute the corresponding sub-templates, so that the header and footer are independent and content contains them both. Note that if we try to execute `s1.Execute`, nothing will be outputted because there is no default sub-template available.
 
-When you don't want to use `{{define}}`, then you can just create a text file with the name of the sub template, for instance `_head.tmpl` is a sub template which you'll use across your project then create this file in the templates folder, and use the normal syntax. Lookup cache is basically created so that you don't read the file every time you serve a request, because if you do, then you are wasting a lot of resources for reading a file which won't change unless the codebase is being rewritten, it doesn't make sense to parse the template files during each HTTP GET request, so the technique is used where we parse the files once and then do a `LookUp()` on the cache to execute the template when we need it to display data.
+When you don't want to use `{{define}}`, then you can just create a text file with the name of the sub template, for instance `_head.tmpl` is a sub template which you'll use across your project then create this file in the templates folder, and use the normal syntax. Lookup cache is basically created so that you don't read the file every time you serve a request, because if you do, then you are wasting a lot of resources for reading a file which won't change unless the codebase is being rewritten, it doesn't make sense to parse the template files during each HTTP GET request, so the technique is used where we parse the files once and then do a `Lookup()` on the cache to execute the template when we need it to display data.
 
 Templates in one set know each other, but you must parse them for every single set.