// Add striped background to tables.
//
// Modified from original to allow ignoring of table rows or cells with
// classes or backgroundColor attributes: 'arguments[3] == true' ignores
// classes.  Defaults to original version to respect classes and
// backgroundColor attribute.
//
// From http://www.alistapart.com/articles/zebratables
 
 
// 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 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";
    var ignoreClasses = arguments[3] ? arguments[3] : false;
  
    // 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
    // <tbody>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 have a class attribute
            // or backgroundColor style.
            if (ignoreClasses || (! hasClass(trs[i]) && ! trs[i].style.backgroundColor)) {
                  
                // 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];

                    // Avoid cells that have a class attribute
                    // or backgroundColor style.
                    if (ignoreClasses || (! hasClass(mytd) && ! mytd.style.backgroundColor)) {
        
                        mytd.style.backgroundColor = even ? evenColor : oddColor;
                    }
                }
            }
            // Flip from odd to even, or vice-versa.
            even =  ! even;
        }
    }
}