using regex in javascript to check if foreign characters : <p>I'm trying to create a simple function that checks if there are foreign characters in my string. Essentially, this is what I'm trying to get:</p>

<pre><code>var str_1 = "отправка.py" // should return true
var str_2 = "bla.py" // should return false
var str_3 = "bla23.py" // should return false
var str_4 = "bla23_.py" // should return false
</code></pre>

<p>I want to make sure that there aren't any foreign characters, while still making sure that I allow everything else (characters like "_", "-", ...). </p>

<p>I'm just trying to avoid the Russian, Mandarin, etc.. alphabets.</p>
