if (document.images) {
	 B1_Lo = new Image();B1_Hi = new Image();
	 B2_Lo = new Image();B2_Hi = new Image();
	 B3_Lo = new Image();B3_Hi = new Image();
	 B4_Lo = new Image();B4_Hi = new Image();
	 B5_Lo = new Image();B5_Hi = new Image();
	 B6_Lo = new Image();B6_Hi = new Image();
	 B7_Lo = new Image();B7_Hi = new Image();
     B1_Lo.src="images/nav/navi_02.gif";
     B1_Hi.src="images/nav/roll/navi_02.gif";  
     B2_Lo.src="images/nav/navi_04.gif";
     B2_Hi.src="images/nav/roll/navi_04.gif"; 
     B3_Lo.src="images/nav/navi_06.gif";
     B3_Hi.src="images/nav/roll/navi_06.gif"; 
     B4_Lo.src="images/nav/navi_08.gif";
     B4_Hi.src="images/nav/roll/navi_08.gif"; 
     B5_Lo.src="images/nav/navi_10.gif";
     B5_Hi.src="images/nav/roll/navi_10.gif"; 
     B6_Lo.src="images/nav/navi_12.gif";
     B6_Hi.src="images/nav/roll/navi_12.gif"; 	 	 	 	 	 
     B7_Lo.src="images/nav/navi_14.gif";
     B7_Hi.src="images/nav/roll/navi_14.gif";    
	}         
  function Roll(ButtonObject, ButLo) 
    {if(ButLo && document.images) ButtonObject.src = ButLo.src;}