Simple JavaScript Password protection not working on mobile platfrom

Simple JavaScript Password protection not working on mobile platfrom

<script language="JavaScript">
var password;
var pass1="apple";
password=prompt('Password?',' ');
if (password!=pass1) {window.location="WRONG.html";}
</script>
This code works fine on desktop chrome, firefox, safari, ect. But when I
load the page in a mobile browser such as mobile chrome or mobile safari,
I am redirected towards "wrong.html" every time. What am I missing?
Thanks!