Popup Example:

Click Here For an Online Map to LoudOffice.com

JAVASCRIPT:
<SCRIPT LANGUAGE=JAVASCRIPT> <!-- function mappopup() { mapwin = window.open("http://maps.yahoo.com/py/maps.py?BFCat=&Pyt=Tmap&newFL=Use+Address+Below&addr=16+Front+Street&csz=01970&Country=us&Get%A0Map=Get+Map", "MapWin", "status=no,toolbar=no,scrollbars=yes,location=no,menu=yes,width=650,height=545,resizable=yes,screenX=10,screenY=10,top=10,left=10"); } // --> </SCRIPT>

BODY:
<a href="javascript:mappopup()">Click Here For an Online Map to LoudOffice.com</a>

Form Button

<input type="button" value="Click Me" onClick="javascript:alert('I have been clicked');">

Changing the Source of an Image

Most sites have some sort of navigation setup that features images that change when you mouse over them.  An example is on the LoudOffice.com website.  The easiest way to do this is via a set of functions that a graphics program such as Fireworks creates for you, however it is possible to do this on your own.  Below is a very basic example:

<p><a href="#" onMouseOver="document.image_name.src='http://www.loudoffice.com/class/images/mouseover_two.gif'" onMouseOut="document.image_name.src='http://www.loudoffice.com/class/images/mouseover_one.gif'"> <img src="http://www.loudoffice.com/class/images/mouseover_one.gif" name="image_name" border="0" width="290" height="40"></a></p>