function toggleLayer(blockName, styleName){

    var style2
    if (document.getElementById){
        // this is the way the standards work
        style2 = document.getElementById(blockName).style;
    }else if (document.all){
        // this is the way old msie versions work
        style2 = document.all[blockName].style;
    }else if (document.layers){
        // this is the way nn4 works
        style2 = document.layers[blockName].style;
    }

    style2.display = styleName;
}