function render_markdown() {
data = document.getElementById('render_contect').innerHTML;
data = data.replace(/\*\*((?:(?!\*\*).)+)\*\*/, '$1');
data = data.replace(/__((?:(?!__).)+)__/, '$1');
data = data.replace(/\*((?:(?!\*).)+)\*/, '$1');
data = data.replace(/_((?:(?!_).)+)_/, '$1');
document.getElementById('render_contect').innerHTML = data;
}