Selectors: How can I select this Box ?

Selectors: How can I select this Box ?

Hello,
it drivs me crazy, that I don't know how to select this element.
I got a HTML-Code like this:
 <div class='blogbox' id="4">
                                <div class='blogdate'>16.July 2012</div>
                                <h2 class='blogheadline'>Title</h2>
                                <div class='blogtext'>Previewtext</div>
                                <div class='blogimage'>
                                    <img src='images/Blogimages/asdf.png' width='140px' height='140px' alt='blogimage' />
                                </div>
                                <div style='clear:both'></div>
                                <input type='submit' class='submit' value='Read More'/>
                        </div>

Know I want to select the class="blogtext" when I click on the submit-button, but just the blogtext div in the same blogbox like the submit button, so that not every blogtext (class="blogtext ") change, but the  blogtext of the button I've clicked.

I'm from Germany, so please forgive my failures.

Tim Pfeifle