I have 1 page and this page has button when cliek this button, it pop up new window, I use image instead of button.

The problem is when new window pop up, old windows refresh itself 1 time, why it refresh? how to prevent?

This is my code

PHP Code:
<input type=image src='emotion.gif'
onclick='exmp=window.open("smile.php","isag","toolbar=0, menubar=0, scrollbars=yes, resizable=yes");'