/*--------------------------------------------------------------------------*/
/* show or hidden corrected text : toggle */
function show_correctedText( obj ){
    var nextObj = obj.nextSibling;
    
    if ( nextObj.style.display == "block" ){
        nextObj.style.display = "none";
        obj.childNodes[0].textContent = "▶";
        obj.childNodes[1].textContent = "Show corrected text";
    }
    else{
        nextObj.style.display = "block";
        obj.childNodes[0].textContent = String.fromCharCode(9660);
        obj.childNodes[1].textContent = "Hide corrected text";
    }

}