CSS: Positioning
Layout-Single Pixel .gif Trick

I'm
using a single pixel gif to create a the margin indent at the beginning of the
paragraph you're reading. When placing an image on your page, you can identify
height and width to stretch the image larger or smaller. The singel pixel gif
trick uses this to help you control your margins and create a more asthetically
pleasing page. Other attributes you can use with the <img> tag are those
of hspace and vspace.
By using a transparent/clear, single pixel image, with hspace=x and vspace=y
arguments in the <img> tag, you can position the elements on your page
where you want them. The examples below will give you an idea of the
differences between width(hspace)/height(vspace).

This
has 5 pixels of hspace on either side.

This
has 25 pixels of hspace on either side.

This has a width of 5 pixels.

This has a width of 25 pixels.

This has a width of 25 pixels and a height of 5 pixels.