function getCursor(input){
    var result = {start: 0, end: 0};
    if (input.setSelectionRange){
        result.start= input.selectionStart;
        result.end = input.selectionEnd;
    } else if (!document.selection) {
        return false;
    } else if (document.selection && document.selection.createRange) {
        var range = document.selection.createRange();
        var stored_range = range.duplicate();
        stored_range.moveToElementText(input);
        stored_range.setEndPoint('EndToEnd', range);
        result.start = stored_range.text.length - range.text.length;
        result.end = result.start + range.text.length;
    }
    return result;
}

function setCursor(txtarea, start, end){
    if(txtarea.createTextRange) {
        var range = txtarea.createTextRange();
        range.move("character", start);
        range.select();
    } else if(txtarea.selectionStart) {
        txtarea.setSelectionRange(start, end);
    }
}

function insert_tag(startTag, endTag, obj){

    var txtarea = $('#comment', $(obj).parent().parent().parent()).get(0);
    txtarea.focus();

    var scrtop = txtarea.scrollTop;

    var cursorPos = getCursor(txtarea);
    var txt_pre = txtarea.value.substring(0, cursorPos.start);
    var txt_sel = txtarea.value.substring(cursorPos.start, cursorPos.end);
    var txt_aft = txtarea.value.substring(cursorPos.end);

    if (cursorPos.start == cursorPos.end){
        var nuCursorPos = cursorPos.start + startTag.length;
    }else{
        var nuCursorPos=String(txt_pre + startTag + txt_sel + endTag).length;
    }
    txtarea.value = txt_pre + startTag + txt_sel + endTag + txt_aft;
    setCursor(txtarea,nuCursorPos,nuCursorPos);

    if (scrtop) txtarea.scrollTop=scrtop;
}

function insert_text(obj, tagName){
    var startTag = '<' + tagName + '>';
    var endTag = '</' + tagName + '>';
    insert_tag(startTag, endTag, obj);
    return false;
}

function insert_smile(obj, tagName){
    insert_tag(tagName + " ", '', obj);
    return false;
}