# Option: onchange_callback

This option should contain a function name to be executed each time contents is modified by TinyMCE. This function is called each time a undo level is added to TinyMCE. The format of this function is: onchange(inst), where inst is the editor instance object reference.

### Example of usage of the onchange_callback option:

    function myCustomOnChangeHandler(inst) {
        alert("Some one modified something");
        alert("The HTML is now:" + inst.getBody().innerHTML);
    }

    tinyMCE.init({
        ...
        onchange_callback : "myCustomOnChangeHandler"
    });