function highlightTableRows( tableId ) {

    var previousClass = null;
    var table = document.getElementById(tableId);
    var tbody = table.getElementsByTagName( "tbody")[0];
    var rows = tbody.getElementsByTagName("tr");

    // add event handlers so rows light up and are clickable

    for( i = 0; i < rows.length; i++ ) {
        rows[i].onmouseover = function() {
            previousClass = this.className;
            this.className += ' over'
        };
        rows[i].onmouseout = function() {
            this.className = previousClass
        };
    }
}

function numbersOnly( event ) {

    var keynum;
    var numcheck;

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

    if( keynum == null )
        return true;

    // Possible numbers or 'backspace' only

    return (keynum >= 48 && keynum <= 57) || keynum == 8;
}

// Show the document's title on the status bar

window.defaultStatus = document.title;