Question

Basically I have something like this:

<script>
    function myfunction(){
        var data = CKEDITOR.instances.editable.getData();
        alert(data);
    }
</script>

What I want to do is, if data does not match this:

<h2>Any text allowed here but only text<h2> 

I want to warn the user.
How can I do this?
Thank you..

I will edit my question, I guess it was not clear enough..

the data variable is read from somewhere. It is not important.
When a button is clicked, this function is called.
The data variable ( which is a string ) can only be something like this:

<h2> ANY TEXT HERE </h2>

So these are not allowed:

Anytext
<h1>any text</h1>
<a href=..>

Thank you.

Answer 1

Version 1:

var pattern = /<h2>[^\d]+<\/h2>/;
console.log(pattern.test('<h2>asf</h2>'));

This will prevent any numbers but accept only plain letters.

Version 2:

var pattern = /<h2>[A-Za-z]+<\/h2>/;
    console.log(pattern.test('<h2>asf</h2>'));

Which will accept A-Za-z only inbetween tags

Version 3:

   var pattern = /<h2>[^\<\>\/\d]+<\/h2>/;
    console.log(pattern.test('<h2>asf?1.,</h2>'));

This will accept anything except numbers and to prevent any closing tags