//showhiddendivs for transit main page
//works along with rotateTransitImages.js - must adjust opacity of
//background images if the link div is selected so that the 
//user can see the links easier.

//clearShowingDivs is used if ferry or bus is selected and a div is showing
//since there is no hidden link div for ferry or bus, just clear the one for
//either railroad or subway depending on which is showing and do nothing else

//use global variables to store previously selected divs
//and to see whether a div has been selected or not
var divShowing = false;
var visibleDiv = "";
var visibleDivNumber; //passed in with mouse over to show image selected
var divOpacity = 80;

function showHiddenDiv(selectedDiv) {
    var newDivToShow = new getObj(selectedDiv+'Div');
    var newTD = new getObj(selectedDiv + 'TD');
    
    if (divShowing) {
        //need to clear existing showing div and reset opacity to 100
        hideHiddenDiv(visibleDiv);
    }
    
    //change background image to faded image
    newTD.style.backgroundImage = "url(./images/" + selectedDiv + "BGFaded.gif)";
    newDivToShow.style.visibility = "visible";
    
    //now set current div to visible div
    //newDivToShow.style.visibility = "visible";
    visibleDiv = selectedDiv;
    //visibleDivNumber = divNumber;
    divShowing = true;
    
}

function hideHiddenDiv(selectedDiv) {
	//return image back to normal state and hiden div
	if (selectedDiv != "") {
        var newDivToShow = new getObj(selectedDiv+'Div');
        var newTD = new getObj(selectedDiv + 'TD');
    
        newTD.style.backgroundImage = "url(./images/" + selectedDiv + "BG.gif)";
        newDivToShow.style.visibility = "hidden";
    }
    else {
        if (visibleDiv != "") {
            var newDivToShow = new getObj(visibleDiv+'Div');
            var newTD = new getObj(visibleDiv + 'TD');
    
			newTD.style.backgroundImage = "url(./images/" + visibleDiv + "BG.gif)";
			newDivToShow.style.visibility = "hidden";
			visibleDiv = "";
        }
    }
}