/*
Alternating row color script by Joost de Valk ( http://www.joostdevalk.nl/ ) to add alternating row classes to a table.
Copyright (c) 2006 Joost de Valk.
*/

/* Don't change anything below this unless you know what you're doing */
addevent(window, "load", alternate_init);

function alternate_init() {
    // Find all tables with class sortable and make them sortable
    if (!document.getElementsByTagName) return;
    tbls = document.getElementsByTagName("table");
    for (ti = 0; ti < tbls.length; ti++) {
        thisTbl = tbls[ti];
        if (((' ' + thisTbl.className + ' ').indexOf("timetable") != -1) && (thisTbl.id)) {
            alternate(thisTbl);
        }
    }
}

function addevent(elm, evType, fn, useCapture)
// addrowtwot and removerowtwot
// cross-browser rowtwot handling for IE5+,	NS6 and Mozilla
// By Scott Andrew
{
    if (elm.addEventListener) {
        elm.addEventListener(evType, fn, useCapture);
        return true;
    } else if (elm.attachEvent) {
        var r = elm.attachEvent("on" + evType, fn);
        return r;
    } else {
        alert("Handler could not be removed");
    }
}

function replace(s, t, u) {
    /*
    **  Replace a token in a string
    **    s  string to be processed
    **    t  token to be found and removed
    **    u  token to be inserted
    **  returns new String
    */
    i = s.indexOf(t);
    r = "";
    if (i == -1) return s;
    r += s.substring(0, i) + u;
    if (i + t.length < s.length)
        r += replace(s.substring(i + t.length, s.length), t, u);
    return r;
}

function alternate(table) {
    // Take object table and get all it's tbodies.
    var tableBodies = table.getElementsByTagName("tbody");
    // Loop through these tbodies
    for (var i = 0; i < tableBodies.length; i++) {
        // Take the tbody, and get all it's rows
        var tableRows = tableBodies[i].getElementsByTagName("tr");
        // Loop through these rows
        for (var j = 1; j < tableRows.length; j++) {
            // Check if j is rowtwo, and apply classes for both possible results
            if ((j % 2) == 0) {
                if (tableRows[j].className == 'rowone' || !(tableRows[j].className.indexOf('rowone') == -1)) {
                    tableRows[j].className = replace(tableRows[j].className, 'rowone', 'rowtwo');
                } else {
                    tableRows[j].className += "rowtwo";
                }
            } else {
                if (tableRows[j].className == 'rowtwo' || !(tableRows[j].className.indexOf('rowtwo') == -1)) {
                    tableRows[j].className = replace(tableRows[j].className, 'rowtwo', 'rowone');
                }
                tableRows[j].className += " rowone";
            }
        }
    }
}