if( document.images )
{
<!--Small button-->
  but1 = new Image() ;
  but1.src = "images/button1_off.gif";
  but2 = new Image(152,21) ;
  but2.src = "images/button1_on.gif";

  but3 = new Image(152,21) ;
  but3.src = "images/button2_off.gif";
  but4 = new Image(152,21) ;
  but4.src = "images/button2_on.gif";
  
  but5 = new Image(152,21) ;
  but5.src = "images/button3_off.gif";
  but6 = new Image(152,21) ;
  but6.src = "images/button3_on.gif";

  but7 = new Image(152,21) ;
  but7.src = "images/button4_off.gif";
  but8 = new Image(152,21) ;
  but8.src = "images/button4_on.gif";  

  but9 = new Image(152,21) ;
  but9.src = "images/button5_off.gif";
  but10 = new Image(152,21) ;
  but10.src = "images/button5_on.gif"; 
  
  but11 = new Image(152,21) ;
  but11.src = "images/button6_off.gif";
  but12 = new Image(152,21) ;
  but12.src = "images/button6_on.gif"; 
  
  
  but13 = new Image(152,21) ;
  but13.src = "images/bot_button1_off.gif";
  but14 = new Image(152,21) ;
  but14.src = "images/bot_button1_on.gif"; 
  
  but15 = new Image(152,21) ;
  but15.src = "images/bot_button2_off.gif";
  but16 = new Image(152,21) ;
  but16.src = "images/bot_button2_on.gif"; 
  
  but17 = new Image(152,21) ;
  but17.src = "images/bot_button3_off.gif";
  but18 = new Image(152,21) ;
  but18.src = "images/bot_button3_on.gif"; 
  
  but19 = new Image(152,21) ;
  but19.src = "images/bot_button4_off.gif";
  but20 = new Image(152,21) ;
  but20.src = "images/bot_button4_on.gif"; 
  
    
  but21 = new Image(152,21) ;
  but21.src = "images/bot_button5_off.gif";
  but22 = new Image(152,21) ;
  but22.src = "images/bot_button5_on.gif"; 
  }

<!--
function chkVer(imagename,objectsrc)
{
var n=navigator.appName
var v=parseInt(navigator.appVersion)
var browsok=((n=="Netscape")&&(v>=3))
var browsok2=((n=="Microsoft Internet Explorer")&&(v>=4))
if ((browsok)||(browsok2))
document.images[imagename].src=eval(objectsrc+".src")
}
//-->