URL filter with str_replace
<p>I've input field where visitor will have to enter URL and some may enter just <code>www.some_site.com</code> or <code>http://www.some_site.com</code> or <code>https://www.some_site.com</code>
or even <code>some_site.com</code>.</p>

<p>i want no matter they entered is to make the output like <code>http://www.some_site.com</code></p>

<p>will i use <code>str_replace</code> but how.</p>

<p>~ any help or idea else.</p>
