ns4   = (document.layers);
ie4   = (document.all);
ns6   = (navigator.userAgent.indexOf("Netscape6") != -1);
ver4  = ( ns4 || ie4 || ns6);   
isMac = (navigator.appVersion.indexOf("Mac") != -1);

var imgNames = new Array("stack","company","products","solutions","contactus","careers","blank");
//var imgNames = new Array("stack","company","products","solutions","contactus","whatsnew","career//s");


// just preload the highlight version of menu buttons.
// the others will load when the page loads.

if (document.images) 
{
  for( i = 0 ; i < imgNames.length ; i++ )
  {
     eval( imgNames[i] + 'i_h = new Image;');
     eval( imgNames[i] + 'i_h.src=" images\/' + imgNames[i] + '_h.gif"' ) ;
   }
}
		
function switchImg( namein , highlight )
{
   var suf  = highlight ? '_h' : '' ;
   var img  = namein + suf ;
   var rollid = namein + 'r' ;

   document[namein].src= 'images/' + img + '.gif' ;

   var vis = highlight ? show( rollid ) : hide( rollid );;
}