// slides.js	for RTG slide shows

var isNS = false;		// Netscape 4?
var isN6 = false;		// Netscape 6?
var isIE = false;		// Internet Explorer 4+?

// Called from onLoad() in BODY tag.  When page is loaded, removes "loading" message
// and shows right arrow.
function Setup(){
	// Test for IE before NS6, because it has both document.all and document.getElementByID
	
	// alert( "Setup" );
	
	if( document.layers )		// Netscape 4 browser?
		isNS = true;
	else if( document.all )		// IE4+
		isIE = true;
	else if( document.getElementById )		// Netscape 6 & other DOM1 browsers
		isN6 = true;
	else
		alert( "Unsupported browser" );
	showLayer( "nextbutton", 0 );
	hideLayer( "loadmsg" );
}

// Show the named layer with the specified Z index (an integer)
// 0 is the default layer, -1 is below it, 1 is above it
function showLayer( layerID, z ){
	//alert( "showLayer " + layerID );
	
	if( isNS ){	// Netscape
		document.layers[layerID].zIndex = z;	
		document.layers[layerID].visibility = "show";
	}
	else if( isN6 ){
		document.getElementById(layerID).style.zIndex = z;
		document.getElementById(layerID).style.visibility = "visible";
	}
	else{		// IE
		document.all[layerID].style.zIndex = z;
		document.all[layerID].style.visibility = "visible";
	}
}
// Hide the named layer
function hideLayer( layerID ){
	// alert( "hide layer: " + layerID );
	
	if( isNS )	// Netscape
		document.layers[layerID].visibility = "hide";
	else if( isN6 )
		document.getElementById(layerID).style.visibility = "hidden";
	else					// IE
		document.all[layerID].style.visibility = "hidden";
}

// The End