//declarations

nav_events_out = new Image ( );
nav_events_out.src = "images/nav_events_out.gif";

nav_events_over = new Image ( );
nav_events_over.src = "images/nav_events_over.gif";

nav_gallery_out = new Image ( );
nav_gallery_out.src = "images/nav_gallery_out.gif";

nav_gallery_over = new Image ( );
nav_gallery_over.src = "images/nav_gallery_over.gif";

nav_contact_out = new Image ( );
nav_contact_out.src = "images/nav_contact_out.gif";

nav_contact_over = new Image ( );
nav_contact_over.src = "images/nav_contact_over.gif";


//browser version detection

var browserName=navigator.appName;
var browserVer=parseInt(navigator.appVersion);
var version="x";

if (browserName=="Netscape" && browserVer>=3) {
	version="n3";
}
else if (browserName=="Microsoft Internet Explorer" && browserVer>=4) {
	version="e4";
}


//functions

function button_on ( imgName )
{
  if ( version == "n3" || version == "e4" )
  {
    butOn = eval ( imgName + "_over.src" );
    document [imgName].src = butOn;
  }
}

function button_off ( imgName )
{
  if ( version == "n3" || version == "e4" )
  {
    butOff = eval ( imgName + "_out.src" );
    document [imgName].src = butOff;
  }
}