If you are looking for solution to auto resize googleadsense ads base on visitor screen size then you are at correct place. below are the solution which allow you to resize ads unit 320×100 , 468×60 , 728×90 and this option is approved by google as well so you dont need to worry about adsense policy.
This example shows you how to modify your responsive code to set specific ad unit sizes for three ranges of screen widths, i.e., mobile, tablet and desktop. You don’t need to have any previous experience of CSS media queries or modifying AdSense ad code to follow this example.
Here’s some modified responsive ad code that sets the following exact ad unit sizes per screen width:
For screen widths up to 500px: a 320×100 ad unit.
For screen widths between 500px and 799px: a 468×60 ad unit.
For screen widths of 800px and wider: a 728×90 ad unit.