var NE4 = document.layers ? true : false;
var IE4 = document.all ? true : false;
var previousDiv = 0;
var visibleDiv = 1;
var nextDiv = 2;

function newImage(arg)
{
	if (document.images) {
		rslt = new Image();
		rslt.src = arg;
		return rslt;
	}
}

function centerButtons() {
	var headerWidth = 750;
	if (IE4 == true) {
		
		//alert(Math.floor((document.body.clientWidth - headerWidth)/2));
		var width = Math.floor((document.body.clientWidth - headerWidth)/2);
		//alert(width);
		for (var i=1;i<=numDiv;i++) {
			eval("document.all.buttons" + i + ".style.left = width;");
		}
		//document.all.buttons1.style.left = width;
		//document.all.buttons2.style.left = width;
	}
}

function initPage() {
	//alert("loading")
	showButtons(1);
	for(var j=2;j<=numDiv;j++) {
		hideButtons(j);
	}
	//hideButtons(2);
	centerButtons();
	//preLoad();
}

function forwardDiv() {
	if (nextDiv <= numDiv) {
		hideButtons(visibleDiv);
		showButtons(nextDiv);
		previousDiv = visibleDiv;
		visibleDiv = nextDiv;
		nextDiv++;
	}
}

function backwardDiv() {
	if (previousDiv >= 1) {
		hideButtons(visibleDiv);
		showButtons(previousDiv);
		nextDiv = visibleDiv;
		visibleDiv = previousDiv;
		previousDiv--;
	}
}

function changeDiv() {
	
	hideButtons(visibleDiv);
	showButtons(nextDiv);
		
	visibleDiv = nextDiv;
	nextDiv++;
	if (nextDiv > numDiv) nextDiv = 1;
}

function hideButtons(num) {
	var range, styleObj;
	var visibility = ".visibility";

	//set variables for Internet Explorer
	if ( IE4 == true  ){
	  range = "all.";
  	  styleObj = ".style";
	} else {
		range = "";
		styleObj = "";
	}
	eval( "document." + range + "buttons" + num + styleObj + visibility + " = \"hidden\"" ); //hidden or visible
}

function showButtons(num) {
	var range, styleObj;
	var visibility = ".visibility";

	//set variables for Internet Explorer
	if ( IE4 == true  ){
	  range = "all.";
  	  styleObj = ".style";
	} else {
		range = "";
		styleObj = "";
	}
	eval( "document." + range + "buttons" + num + styleObj + visibility + " = \"visible\"" ); //hidden or visible
}

function setMsg( msg )
{
	window.status = msg;
	return true;
}
	
function changeImage( imgName, imgOver, imgExt, imgLayer )
{
	var imgDir = "login/images/navigation/";
	//images are of the form
	//imgNameimgOver.imgExt  
	//onMouseOver imgOver should be someing like "-over", "b", "on", etc 
	//onMouseOut imgOver should be "" so that the original img is put back
	
	//imgName must also be the name of the img <img name='imgName' ....
	//for this script to work properly
	//alert(document.buttons1.document.page1.src);
	if ( NE4 == true  ){
		eval( "document." + imgLayer + ".document." + imgName + ".src = \"" + imgDir + imgName + imgOver + "." + imgExt + "\"" );
	} else {
		eval("document." + imgName + ".src = \"" + imgDir + imgName + imgOver + "." + imgExt + "\"");
	} 
}


onload=initPage
onresize = centerButtons