create a pop up exit with blogspot

In your dashboard click the 'layout' tab, and then 'edit html'. In between your <head> and </head> tags you need to add this code:

<script language='javascript'>
var exitpop = true;
function popup(){

if(exitpop==true) { window.open('http://www.google.com') }
}
</script>


And then you need to change your <body> tag to this:
<body onunload='popup()'>
'Save Template' and that's it

Whoops almost forgot to add:
Now if you don't want the popup to be triggered when a user clicks a particular link (ie and internal link on your blog), you need to select the 'Expand Widget Templates' checkbox, and manually edit each link to add 'onclick="exitpop=false"':

<a onclick='exitpop=false' ...