SetTimeout() Syntax Convert Expression To Literal String?

<p> Howdy <p> expressed as a literal string that is passed to the setTimeout() function might look like this: setTimeout("document.getElementById('first').innerHTML = '<p>' + 'HOWDY' + '</p>';", 2000);

I guess you can't just put quotes around an expression like this: "'<p> HOWDY </p>;" So tags have to be isolated, but it get confusing with expressions like this, which I am not sure how to express as a string:

<p><h2 class="pos_left"> <img src="car1.jpg" name="slide" width="400" height="250" /> </h2> </p>

I wish I could change the " in there to ' and then just wrap the whole thing in double " This is what I came up with but it did not work: setTimeout("document.getElementById('first').innerHTML = '<p>' + '<h2' + 'class='pos_left'' + '>' + '<img' + 'src='car1.jpg'' + 'name='slide'' + 'width='400'' + 'height='250'' + '/>' + '</h2>' + '</p>';", 4000);