// this function is needed to work around 
// a bug in IE related to element attributes
function hasClass(obj) {
    var result = false;
    if (obj.getAttributeNode("class") != null) {
        result = obj.getAttributeNode("class").value;
    }
    return result;
}   

function setStyle(elements, property, value) {
    if (!elements) { return; }
    if (elements.length == 0) {
        return;
    } else if (!elements.length) {
        elements.style[property] = value;
    }
    else {
        for (var i = 0; i < elements.length; i++) {
            elements[i].style[property] = value;
        }
    }
}

// Finds a stylesheet rule and sets a property.
function setStyleProperty(selectorText, property, newValue) {
    // Can be lots of sheets with a document
    for (var sheetI = 0; sheetI < document.styleSheets.length; sheetI++) {
       var sheet = document.styleSheets[sheetI];
       // And, of course, lots of rules in a stylesheet
       for (var ruleI = 0; ruleI < sheet.cssRules.length; ruleI++) {
           var rule = sheet.cssRules[ruleI];
           if (rule.selectorText == selectorText) {
               // What the hell is the last parameter for this function?
               rule.style.setProperty(property, newValue, "");
           }
       }
    }
}

function stripe(id) {

    // the flag we'll use to keep track of 
    // whether the current row is odd or even
    var even = false;

    // if arguments are provided to specify the colours
    // of the even & odd rows, then use the them;
    // otherwise use the following defaults:
    var evenColor = arguments[1] ? arguments[1] : "#fff";
    var oddColor = arguments[2] ? arguments[2] : "#eee";

    // obtain a reference to the desired table
    // if no such table exists, abort
    var table = document.getElementById(id);
    if (! table) { return; }

    // by definition, tables can have more than one tbody
    // element, so we'll have to get the list of child
    // &lt;tbody&gt;s 
    var tbodies = table.getElementsByTagName("tbody");

    // and iterate through them...
    for (var h = 0; h < tbodies.length; h++) {

        // find all the &lt;tr&gt; elements... 
        var trs = tbodies[h].getElementsByTagName("tr");

        // ... and iterate through them
        for (var i = 0; i < trs.length; i++) {

            // avoid rows that don't display
            if (trs[i].style.display != "none") {

                // get all the cells in this row...
                var tds = trs[i].getElementsByTagName("td");

                // and iterate through them...
                for (var j = 0; j < tds.length; j++) {

                    var mytd = tds[j];

                    mytd.style.backgroundColor =
                        even ? evenColor : oddColor;

                }
                // flip from odd to even, or vice-versa
                even =  ! even;
            }
        }
    }
}