BODY { position: relative; min-width: 600px; width: 100%; margin: 0; padding: 0; }
#header { position: absolute; top: 0; left: 0; min-width: 600px; width: 100%; height: 100px; }
#menu { position: absolute; top:100px; left: 0; width: 19%;  margin: 1% 1% 0 0; }
#content { position: absolute; top:100px; left:20%; min-width: 360px; width: 60%; margin-top: 1%; }
#credit { position: absolute; top:100px; left: 80%; width: 19%; margin: 1% 0 0 1%; }

/* HR styles need for IE/Win. */
HR.holder { width:600px; visibility: hidden; } /* Equal to 'top' */
HR.left, HR.right { width: 120px; visibility: hidden; }
HR.middle { width: 360px; visibility: hidden; } 

/* These HR styles replace the above, and are need for Netscape 4.x. 
   Left and right margins are half the relevant DIV width */
HR.holder { width:0; margin: 0 300px; } /* Equal to 'top' */
HR.left, HR.right { width: 0; margin: 0 60px; }
HR.middle { width: 0; margin: 0 180px;  } 

/* DIVs must have a border value set in Netscape 4.x */
DIV { border: none; }

<!--[if lt IE 6]>
<style type="text/css" screen="media"><!--
/* HR styles need for IE 5/Win and under. */
#content { position: relative; }
<![endif]-->