onChange designates a JavaScript to run when the user chooses one of the options. This means that an action is initiated immediately when the user chooses an item, not when a "submit" button is pressed. A popular use for onChange is to make the <SELECT ...> list a set of hyperlinks. This allows you to display many links in a very compact space:
<FORM>
<SELECT ONCHANGE="location = this.options[this.selectedIndex].value;">
<OPTION VALUE="myhome.html">My Home Page
<OPTION VALUE="myResume.html">Resume
<OPTION VALUE="myhobbies.html">Hobbies
<OPTION VALUE="mydog.html">My Dog
</SELECT>
</FORM>
which gives us
It's usually better to use a submit button instead of onChange. The interface is cleaner if you separate the actions of selecting a destination and of saying "now go". See Drop Down Menu Tutorial for complete code and examples.