browser_name = navigator.appName;
browser_version = parseFloat(navigator.appVersion);

if (browser_name == "Netscape" && browser_version >= 3.0) { roll = 'true'; }
else if (browser_name == "Microsoft Internet Explorer" && browser_version >= 4.0) { roll = 'true'; }
else { roll = 'false'; }

function msover1(img1,ref1) { if (roll == 'true') { document.images[img1].src = ref1; } }
function msout1(img1,ref1) { if (roll == 'true') { document.images[img1].src = ref1; } }

function msover2(img1,ref1,img2,ref2) { if (roll == 'true')
        { document.images[img1].src = ref1; document.images[img2].src = ref2;} }

function msout2(img1,ref1) { if (roll == 'true')
        { document.images[img1].src = ref1; } }

function msover3(img1,ref1,img2,ref2,img3,ref3) { if (roll == 'true')
        { document.images[img1].src = ref1; document.images[img2].src = ref2; document.images[img3].src = ref3;         } }
function msout3(img1,ref1,img2,ref2) { if (roll == 'true')
        { document.images[img1].src = ref1; document.images[img2].src = ref2; } }