Getting rid of the secure/non secure message in IE when using a form

Getting rid of the secure/non secure message in IE when using a form

Hi,
I created a Zoho form. In Internet Explorer, when users bring up the form, many receive a message that the page contains both secure and nosecure items..." do they want to display the nonsecure item. This may have to do with the fact that our site now features a https URL (new SSL). I'm not sure if that's coinciding with this issue. Is there a way to change my Zoho form so that the secure/non secure message won't appear for IE users without having to give them instructions for changing their browser settings. Does this have to do with the form using an 'iframe?' Any info/help is appreciated. Thanks a lot.