function toggleMonthSelect()
{
    var monthfield = document.getElementById("CAmonthField");
    var yearfield = document.getElementById("CAyearField");
    
    if (monthfield && yearfield) monthfield.disabled = (yearfield.selectedIndex == 0);    
}

function paramSearch()
{
    var monthfield = document.getElementById("CAmonthField");
    var yearfield = document.getElementById("CAyearField");
    var topicfield = document.getElementById("CAtopicField");
    
    if (monthfield && yearfield && topicfield)
    {
        var query = '';
        query += (yearfield.selectedIndex != 0) ?  'y=' + yearfield.options[yearfield.selectedIndex].value + "&" : '';
        query += ((yearfield.selectedIndex != 0) && (monthfield.selectedIndex != 0)) ?  'm=' + monthfield.options[monthfield.selectedIndex].value + "&" : '';
        query += (topicfield.selectedIndex != 0) ?  'c=' + topicfield.options[topicfield.selectedIndex].value + "&" : '';
       
        location.href = CAsubmitURL + '?' + query;

    }
}

function keywordSearch()
{
    var keywordfield = document.getElementById("CAkeywordField");
    
    if (keywordfield)
    {
        var query = '';
        query += (keywordfield.value != '') ?  'k=' + keywordfield.value : '';
        
        if (query != '') location.href = CAsubmitURL + '?' + query;
        if (query == '') alert('Please enter a keyword');
    }
}

function searchOnEnter(tKey)
{
    var keynum;
    if(window.event) // IE
    {
        keynum = tKey.keyCode;
    }
    else if(tKey.which) // Netscape/Firefox/Opera
    {
        keynum = tKey.which;
    }

    if(keynum==13) keywordSearch();
}