The short answer is yes.
This is how I see it...
You want your drop down box to allow the user to select a different page,
When a user submits the form the new page is loaded.
Now javascript is an event driven language (things happen at certain instances) and there are more than one events happening in your example.
When an event happens you can use javascript to 'capture' the event and act accordingly to how you've scripted.
The first event is that the user is selecting a page, this is captured using the onChange event in the Select tag. eg: <select name="mySelectBox" onChange="myFunction()">
The second event is when the user clicks the submit button, this is captured using the onClick event on the Input tag. eg: <input type="submit" onClick="myFunction()">
the third event is the form being submitted, this automatically happens whenever a submit button is clicked, this can be captured by the onSubmit event in the form tag. eg: <form name="form1" onSubmit="myFunction()">
You can't use the onSubmit event on a drop down box because the drop down box doesn't get submitted, it's actually the form that this is happening to, there are many examples of this in javascript and the best way to find them is by trial and error.
Now myFunction is the name of the function you want to run when the event happens, you would need some Script code in your html page that performs when this function is called, as with your first example.
I won't tell you the answer just yet, I'll see if that helps, it'll be better for you if you can work it out yourself, but if you need more help then just as one more time. no problem 
Cheers,
Blaise