Newbie help on this button please!

[Jon Lawrance]

I know very little about javascript but I am trying to interpret what a particular button is doing.

 
<td><a href="<A href="http://mysite.com/xx/xx.php?f=3011&i=16998&sub=selector1"=test-selector">http://mysite.com/xx/xx.php?f=3011&i=16998&sub=selector1"=test-selector" onMouseOut="MM_swapImgRestore()" onMouseOver="MM_swapImage('MyImage','','images/buttons/myimage_border.gif',1)"><img src="images/buttons/myimage.gif" name="MyImage" width="108" height="68" border="0"></a>

Can someone please explain to me? Also, what variable gets passed along, "selector1" or "test-selector"?