// context menu data objects
var cMenu = new Object();
cMenu["lookup1"] = {menuID:"contextMenu1", hrefs:["http://www.usscouts.org","http://www.usscouts.org"]};
cMenu["lookup2"] = {menuID:"contextMenu2", hrefs:["http://www.missouritourism.org","http://www.modot.state.mo.us/roadcond/statemap.htm ","http://www.cnn.com","http://www.google.com","http://www.yahoo.com"]};

// position and display context menu
function showContextMenu(evt) {
    // hide any existing menu just in case
    hideContextMenus();
    evt = (evt) ? evt : ((event) ? event : null);
    if (evt) {
        var elem = (evt.target) ? evt.target : evt.srcElement;
         if (elem.nodeType == 3) {
            elem = elem.parentNode;
        }
        if (elem.className == "contextEntry") {
            var menu = document.getElementById(cMenu[elem.id].menuID);
            // turn on IE mouse capture
            if (menu.setCapture) {
                menu.setCapture();
            }
            // position menu at mouse event location
            var left, top;
            if (evt.pageX) {
                left = evt.pageX;
                top = evt.pageY;
            } else if (evt.offsetX || evt.offsetY) {
                left = evt.offsetX;
                top = evt.offsetY;
            } else if (evt.clientX) {
                left = evt.clientX;
                top = evt.clientY;
            }
            menu.style.left = left + "px";
            menu.style.top = top + "px";
            menu.style.visibility = "visible";
            if (evt.preventDefault) {
                evt.preventDefault();
            }
            evt.returnValue = false;
        }
    }
}

// retrieve URL from cMenu object related to chosen item
function getHref(tdElem) {
    var div = tdElem.parentNode.parentNode.parentNode.parentNode;
    var index = tdElem.parentNode.rowIndex;
    for (var i in cMenu) {
        if (cMenu[i].menuID == div.id) {
            return cMenu[i].hrefs[index];    
        }
    }
    return "";
}

// navigate to chosen menu item
function execMenu(evt) {
    evt = (evt) ? evt : ((event) ? event : null);
    if (evt) {
        var elem = (evt.target) ? evt.target : evt.srcElement;
        if (elem.nodeType == 3) {
            elem = elem.parentNode;
        }
        if (elem.className == "menuItemOn") {
            location.href = getHref(elem);
        }
        hideContextMenus();
    }
}

// hide all context menus
function hideContextMenus() {
    if (document.releaseCapture) {
        // turn off IE mouse event capture
        document.releaseCapture();
    }
    for (var i in cMenu) {
        var div = document.getElementById(cMenu[i].menuID)
        div.style.visibility = "hidden";
    }
}

// rollover highlights of context menu items
function toggleHighlight(evt) {
    evt = (evt) ? evt : ((event) ? event : null);
    if (evt) {
        var elem = (evt.target) ? evt.target : evt.srcElement;
        if (elem.nodeType == 3) {
            elem = elem.parentNode;
        }
        if (elem.className.indexOf("menuItem") != -1) {
            elem.className = (evt.type == "mouseover") ? "menuItemOn" : "menuItem";
        }
    }
}

// set tooltips for menu-capable and lesser browsers
function setContextTitles() {
    var cMenuReady = (document.body.addEventListener || typeof document.oncontextmenu != "undefined")
    var spans = document.body.getElementsByTagName("span");
    for (var i = 0; i < spans.length; i++) {
        if (spans[i].className == "contextEntry") {
            if (cMenuReady) {
                var menuAction = (navigator.userAgent.indexOf("Mac") != -1) ? "Click and hold " : "Right click ";
                spans[i].title = menuAction + "to view relevant links"
            } else {
                spans[i].title = "Relevant links available with other browsers (IE5+/Windows, Netscape 6+)."
                spans[i].style.cursor = "default";
            }
        }
    }
}

// bind events and initialize tooltips
function initContextMenus() {
    if (document.body.addEventListener) {
        // W3C DOM event model
        document.body.addEventListener("contextmenu", showContextMenu, true);
        document.body.addEventListener("click", hideContextMenus, true);
    } else {
        // IE event model
        document.body.oncontextmenu = showContextMenu;
    }
    // set intelligent tooltips
    setContextTitles();
}