Google Chrome https popup error

Question

I have a secure page. In Chrome when I pop-up pages from that secure page, it displays an exclamation mark in both the parent and child address bars.

When viewed on it's own the child page shows as secure (no exclamation mark) according to Chrome.

How can I have popups from my secure page, and not induce these exclamation mark warnings?

Here's my popup code:

function popup(URL) {
        day = new Date();
        id = day.getTime();
        eval("page" + id + " = window.open(URL, '" + id + "', 'toolbar=0,scrollbars=1,location=0,statusbar=0,menubar=0,resizable=1,width=800,height=550');");
    }

Answer 1

Got it sorted. I had 5 popups on my page. Some of those popups had https links, but the content wasn't totally secure. Once I secured all of the popups, the exclamation went away.