How to renew codemirror page?

1

I can add a json to codemirror. But I want to renew page when changed the option of json file. How can i do that?

Here is my code;

var b=document.getElementById(“JsonText”);
var myCodeMirror = CodeMirror(b, {
lineNumbers: true,
value: geojson3,
mode: “application/json”
});