var tabLinks = new Array();
var contentDivs = new Array();

function tabinit() {

    // Grab the tab links and content divs from the page
    var tabListItems = document.getElementById('tabs').childNodes;
    for ( var i = 0; i < tabListItems.length; i++ ) {
        if ( tabListItems[i].nodeName == "LI" ) {
	    var tabLink = getFirstChildWithTagName( tabListItems[i], 'A' );
	    var id = getHash( tabLink.getAttribute('href') );
	    tabLinks[id] = tabLink;
	    contentDivs[id] = document.getElementById( id );
        }
    }

    // Assign onclick events to the tab links, and
    // highlight the first tab
    var i = 0;

    for ( var id in tabLinks ) {
        tabLinks[id].onclick = showTab;
        tabLinks[id].onfocus = function() { this.blur() };
        if ( i == 0 ) tabLinks[id].className = 'selected';
        i++;
    }

    // Hide all content divs except the first
    var i = 0;

    for ( var id in contentDivs ) {
        if ( i != 0 ) contentDivs[id].className = 'tabContent hide';
        i++;
    }
}

function showTab() {
    var selectedId = getHash( this.getAttribute('href') );

    // Highlight the selected tab, and dim all others.
    // Also show the selected content div, and hide all others.
    for ( var id in contentDivs ) {
        if ( id == selectedId ) {
	    tabLinks[id].className = 'selected';
	    contentDivs[id].className = 'tabContent';
        } else {
	    tabLinks[id].className = '';
	    contentDivs[id].className = 'tabContent hide';
        }
    }

    // Stop the browser following the link
    return false;
}

function getFirstChildWithTagName( element, tagName ) {
    for ( var i = 0; i < element.childNodes.length; i++ ) {
        if ( element.childNodes[i].nodeName == tagName ) return element.childNodes[i];
    }
}

function getHash( url ) {
    var hashPos = url.lastIndexOf ( '#' );
    return url.substring( hashPos + 1 );
}