I want to add bold to the (see illustration). If I do this: 

```
        p:function{
        sel = this.getSelection().getRangeAt(0);
        var caretPosition = sel.endOffset;
        var existingText = this.iframe[0].contentWindow.document.body.innerText;

        var before = existingText.substring(0, caretPosition);
        var after = existingText.substring(caretPosition);

        this.iframe[0].contentWindow.document.body.innerHTML= before 
        +'**<b>**(see illustration)**</b>** ' + after;
        },

```

Then all the text that i write after (see illustration becomes bold).

![enter image description here](https://i.stack.imgur.com/L9XIr.png)
![enter image description here](https://i.stack.imgur.com/s1Tbf.png)