lua http.request return attempt to index global 'http' (a nil value)
<p>I just try simple lua code:</p>

<pre><code>local http = require("socket.http")
local  b, c, h = http.request("http://www.example.com/")
</code></pre>

<p>But I get this error:</p>

<pre><code>stdin:1: attempt to index global 'http' (a nil value)
stack traceback:
        stdin:1: in main chunk
        [C]: ?
</code></pre>

<p>luasocket is installed and lua find it, anyone can help?</p>