For create Pop-Ups window use below HTML script which can be used to give source or credits, references, making contact us button or anything you want to make create but don’t need a separate browser window.
All you need to make a pop-up in HTML or blogger/blogspot is to copy the code and paste it where you want to give the link of pop-up and change the desired width, height, toolbar, status bar, scroll bar and link http://djmix4u.blogspot.com/ to according to your requirements.
<a href="http://djmix4u.blogspot.com" onclick="window.open('http://djmix4u.blogspot.com','popup','width=560,height=360,scrollbars=no,resizable=no,toolbar=no,directories=no,location=no,menubar=no,status=no,left=0,top=0'); return false">Click Here</a>