if ( document.images ) {
   web1off = new Image; web1off.src = "./images/homewhite.jpg";
   web1on  = new Image; web1on.src  = "./images/homeblue.jpg";

   web2off = new Image; web2off.src = "./images/blogwhite.jpg";
   web2on  = new Image; web2on.src  = "./images/blogblue.jpg";

   web3off = new Image; web3off.src = "./images/contactswhite.jpg";
   web3on  = new Image; web3on.src  = "./images/contactsblue.jpg";
}

function img_act( imgName ) {
   if ( document.images ) {
       imgOn = eval( imgName + "on.src" );
       document[ imgName ].src = imgOn;
   }
}

function img_inact( imgName ) {
   if ( document.images ) {
       imgOff = eval( imgName + "off.src" );
       document[ imgName ].src = imgOff;
   }
}