Creating a gradient usually involves painting it with photoshop or gimp, then setting it as a background of an element and giving the instruction to repeat horizontally or vertically.
Most of the browsers today allow you to do this by yourself.
To ensure the page will be seen by all browsers just include the following lines in your css class
background: #999; /* for non-css3 browsers */
filter: progid:DXImageTransform.Microsoft.gradient(startColorstr='#ddeeff', endColorstr='#ffffff'); /* for IE */
background: -webkit-gradient(linear, left top, left bottom, from(#ddeeff), to(#ffffff)); /* for webkit browsers */
background: -moz-linear-gradient(top, #ddeeff, #ffffff);
Tags
CSS