function WebForm_FindFirstFocusableChild(control) {

    if (!control || !(control.tagName)) {

        return null;

    }

    var tagName = control.tagName.toLowerCase();

    if (tagName == "undefined") {

        return null;

    }

    var children = control.childNodes;

    if (children) {

        for (var i = 0; i < children.length; i++) {

            try {

                if (WebForm_CanFocus(children[i])) {

                    return children[i];

                }

                else {

                    var focused = WebForm_FindFirstFocusableChild(children[i]);

                    if (WebForm_CanFocus(focused)) {

                        return focused;

                    }

                }

            } catch (e) {

            }

        }

    }

    return null;

}

function WebForm_AutoFocus(focusId) {

    var targetControl;

    if (__nonMSDOMBrowser) {

        targetControl = document.getElementById(focusId);

    }

    else {

        targetControl = document.all[focusId];

    }

    var focused = targetControl;

    if (targetControl && (!WebForm_CanFocus(targetControl)) ) {

        focused = WebForm_FindFirstFocusableChild(targetControl);

    }

    if (focused) {

        try {

            focused.focus();

            if (__nonMSDOMBrowser) {

                focused.scrollIntoView(false);

            }

            if (window.__smartNav) {

                window.__smartNav.ae = focused.id;

            }

        }

        catch (e) {

        }

    }

}

function WebForm_CanFocus(element) {

    if (!element || !(element.tagName)) return false;

    var tagName = element.tagName.toLowerCase();

    return (!(element.disabled) &&

            (!(element.type) || element.type.toLowerCase() != "hidden") &&

            WebForm_IsFocusableTag(tagName) &&

            WebForm_IsInVisibleContainer(element)

            );

}

function WebForm_IsFocusableTag(tagName) {

    return (tagName == "input" ||

            tagName == "textarea" ||

            tagName == "select" ||

            tagName == "button" ||

            tagName == "a");

}

function WebForm_IsInVisibleContainer(ctrl) {

    var current = ctrl;

    while((typeof(current) != "undefined") && (current != null)) {

        if (current.disabled ||

            ( typeof(current.style) != "undefined" &&

            ( ( typeof(current.style.display) != "undefined" &&

                current.style.display == "none") ||

                ( typeof(current.style.visibility) != "undefined" &&

                current.style.visibility == "hidden") ) ) ) {

            return false;

        }

        if (typeof(current.parentNode) != "undefined" &&

                current.parentNode != null &&

                current.parentNode != current &&

                current.parentNode.tagName.toLowerCase() != "body") {

            current = current.parentNode;

        }

        else {

            return true;

        }

    }

    return true;

}