editor.setReadOnly(readOnly)
Allows you to enable/disable read-only mode.
Syntax
            editor.setReadOnly(readOnly)
        
Parameter
Type: boolean
True to make the editor read-only; otherwise, false.
Example:
var editor1 = new RichTextEditor("#div_editor1");      
var toggleBtn=document.getElementById("btn_toggle");      
toggleBtn.onclick=function(){      
    editor1.setReadOnly( ! editor1.getReadOnly() );      
}