Automatically resize images (shrink and expand) when browser is resized in ASP.Net

I have images at the head of the page in an iframe and in the main center page.  The image at the head flows over the social icons and the images at the center page resizing drops below and pushes the other image down.  I just want the images to resize when the browser is being resized.  Please go to http://shopbuyname.com and you'll see what i mean.  Thanks