// Global variables
var isCSS, isW3C, isIE4, isNN4, isIE6CSS;

// Initialize upon load to let all browsers establish content objects
function initDHTMLAPI( ) {
    if (document.images) {
        isCSS = (document.body && document.body.style) ? true : false;
        isW3C = (isCSS && document.getElementById) ? true : false;
        isIE4 = (isCSS && document.all) ? true : false;
        isNN4 = (document.layers) ? true : false;
        isIE6CSS = (document.compatMode && document.compatMode.indexOf("CSS1") >= 0) ? 
        true : false;
    }
}

// Set event handler to initialize API
window.onload = initDHTMLAPI;

// Seek nested NN4 layer from string name
function seekLayer(doc, name) {
    var theObj;
    for (var i = 0; i < doc.layers.length; i++) {
        if (doc.layers[i].name == name) {
            theObj = doc.layers[i];
            break;
        }
        // dive into nested layers if necessary
        if (doc.layers[i].document.layers.length > 0) {
            theObj = seekLayer(document.layers[i].document, name);
        }
    }
    return theObj;
}

// Convert object name string or object reference
// into a valid element object reference
function getRawObject(obj) {
    var theObj;
    if (typeof obj == "string") {
        if (isW3C) {
            theObj = document.getElementById(obj);
        } else if (isIE4) {
            theObj = document.all(obj);
        } else if (isNN4) {
            theObj = seekLayer(document, obj);
        }
    } else {
        // pass through object reference
        theObj = obj;
    }
    return theObj;
}

// Convert object name string or object reference
// into a valid style (or NN4 layer) reference
function getObject(obj) {
    var theObj = getRawObject(obj);
    if (theObj && isCSS) {
        theObj = theObj.style;
    }
    return theObj;
}

// Position an object at a specific pixel coordinate
function shiftTo(obj, x, y) {
    var theObj = getObject(obj);
    if (theObj) {
        if (isCSS) {
            // equalize incorrect numeric value type
            var units = (typeof theObj.left == "string") ? "px" : 0;
            theObj.left = x + units;
            theObj.top = y + units;
        } else if (isNN4) {
            theObj.moveTo(x,y)
        }
    }
}

// Move an object by x and/or y pixels
function shiftBy(obj, deltaX, deltaY) {
    var theObj = getObject(obj);
    if (theObj) {
        if (isCSS) {
            // equalize incorrect numeric value type
            var units = (typeof theObj.left == "string") ? "px" : 0;
            theObj.left = getObjectLeft(obj) + deltaX + units;
            theObj.top = getObjectTop(obj) + deltaY + units;
        } else if (isNN4) {
            theObj.moveBy(deltaX, deltaY);
        }
    }
}

// Set the z-order of an object
function setZIndex(obj, zOrder) {
    var theObj = getObject(obj);
    if (theObj) {
        theObj.zIndex = zOrder;
    }
}

// Set the background color of an object
function setBGColor(obj, color) {
    var theObj = getObject(obj);
    if (theObj) {
        if (isNN4) {
            theObj.bgColor = color;
        } else if (isCSS) {
            theObj.backgroundColor = color;
        }
    }
}

// Set the visibility of an object to visible
function show(obj) {
    var theObj = getObject(obj);
    alert(theObj);
    if (theObj) {
        
        theObj.visibility = "visible";
    }
}

// Set the visibility of an object to hidden
function hide(obj) {
    var theObj = getObject(obj);
    if (theObj) {
        theObj.visibility = "hidden";
    }
}

// Retrieve the x coordinate of a positionable object
function getObjectLeft(obj)  {
    var elem = getRawObject(obj);
    var result = 0;
    if (document.defaultView) {
        var style = document.defaultView;
        var cssDecl = style.getComputedStyle(elem, "");
        result = cssDecl.getPropertyValue("left");
    } else if (elem.currentStyle) {
        result = elem.currentStyle.left;
    } else if (elem.style) {
        result = elem.style.left;
    } else if (isNN4) {
        result = elem.left;
    }
    return parseInt(result);
}

// Retrieve the y coordinate of a positionable object
function getObjectTop(obj)  {
    var elem = getRawObject(obj);
    var result = 0;
    if (document.defaultView) {
        var style = document.defaultView;
        var cssDecl = style.getComputedStyle(elem, "");
        result = cssDecl.getPropertyValue("top");
    } else if (elem.currentStyle) {
        result = elem.currentStyle.top;
    } else if (elem.style) {
        result = elem.style.top;
    } else if (isNN4) {
        result = elem.top;
    }
    return parseInt(result);
}

// Retrieve the rendered width of an element
function getObjectWidth(obj)  {
    var elem = getRawObject(obj);
    var result = 0;
    if (elem.offsetWidth) {
        result = elem.offsetWidth;
    } else if (elem.clip && elem.clip.width) {
        result = elem.clip.width;
    } else if (elem.style && elem.style.pixelWidth) {
        result = elem.style.pixelWidth;
    }
    return parseInt(result);
}

// Retrieve the rendered height of an element
function getObjectHeight(obj)  {
    var elem = getRawObject(obj);
    var result = 0;
    if (elem.offsetHeight) {
        result = elem.offsetHeight;
    } else if (elem.clip && elem.clip.height) {
        result = elem.clip.height;
    } else if (elem.style && elem.style.pixelHeight) {
        result = elem.style.pixelHeight;
    }
    return parseInt(result);
}

// Return the available content width space in browser window
function getInsideWindowWidth( ) {
    if (window.innerWidth) {
        return window.innerWidth;
    } else if (isIE6CSS) {
        // measure the html element's clientWidth
        return document.body.parentElement.clientWidth;
    } else if (document.body && document.body.clientWidth) {
        return document.body.clientWidth;
    }
    return 0;
}

// Return the available content height space in browser window
function getInsideWindowHeight( ) {
    if (window.innerHeight) {
        return window.innerHeight;
    } else if (isIE6CSS) {
        // measure the html element's clientHeight
        return document.body.parentElement.clientHeight;
    } else if (document.body && document.body.clientHeight) {
        return document.body.clientHeight;
    }
    return 0;
}

function getFullHeight() {
    //return (document.height !== undefined) ? document.height : document.body.offsetHeight;
    return document.body.offsetHeight;
}

// Center a positionable element whose name is passed as 
// a parameter in the current window/frame, and show it
function centerOnWindow(elemID) {
    // 'obj' is the positionable object
    var obj = getRawObject(elemID);
    // window scroll factors
    var scrollX = 0, scrollY = 0;
    if (document.body && typeof document.body.scrollTop != "undefined") {
        scrollX += document.body.scrollLeft;
        scrollY += document.body.scrollTop;
        if (document.body.parentNode && 
            typeof document.body.parentNode.scrollTop != "undefined") {
            scrollX += document.body.parentNode.scrollLeft;
            scrollY += document.body.parentNode.scrollTop;
        }
    } else if (typeof window.pageXOffset != "undefined") {
        scrollX += window.pageXOffset;
        scrollY += window.pageYOffset;
    }
    var x = Math.round((getInsideWindowWidth( )/2) - (getObjectWidth(obj)/2)) + scrollX;
    var y = Math.round((getInsideWindowHeight( )/2) - (getObjectHeight(obj)/2)) + scrollY;
    shiftTo(obj, x, y);
//show(obj);
} 

function findPos(obj) {
    var curleft = curtop = 0;
    while (obj) {
        curleft += obj.offsetLeft;
        curtop += obj.offsetTop;
        obj = obj.offsetParent;
    }
    
    return [curleft,curtop];
}

function ShowPopup(hoveritem, message)
{
    hp = document.getElementById("hoverpopup");
    hp.innerHTML = message;
    // Set popup to visible
    var pos = findPos(hoveritem);
    hp.style.top = pos[1]+18;
    hp.style.left = pos[0]+18;
    
    hp.style.visibility = "Visible";
}

function HidePopup()
{
    hp = document.getElementById("hoverpopup");
    hp.style.visibility = "Hidden";	
}

function ShowSmallPopup(hoveritem, id)
{
    hp = document.getElementById(id);
    // Set popup to visible
    var pos = findPos(hoveritem);
    shiftTo(hp, pos[0]-160, pos[1]-70);
    hp.style.background = "white";
    hp.style.width = "200px";

    hp.style.visibility = "Visible";
}

function HideSmallPopup(id)
{
    hp = document.getElementById(id);
    hp.style.visibility = "Hidden";
}

function ShowContactPopup(hoveritem, id)
{
    hp = document.getElementById(id);
    // Set popup to visible
    var pos = findPos(hoveritem);
    shiftTo(hp, pos[0]-320, pos[1]-110);
    
    hp.style.visibility = "Visible";
}

function HideContactPopup(id)
{
    hp = document.getElementById(id);
    hp.style.visibility = "Hidden";	
}

function toggle(obj) {
    var obj = getObject(obj);
    if ( obj.visibility == "visible" ) {
        obj.visibility = "hidden";
        obj.display = "none";
    } else {
        obj.visibility = "visible";
        obj.display = "block";
    }

}