Change every character in a div to a specific character using javascript

Question

Hi,

I am making a page in which many passwords are listed in a div which has an id of pass. I want to use JavaScript to show asterisk(*) in place of every character in that div and i also want to be able to toggle is which means by default when I load the page the passwords should be asterisk but as soon as I click an image the asterisk go away and my passwords should show up can any one help me.

Thanks