UncleRon,
Javascript is the way to do this. It is pretty easy, add something like this to your html code

onClick="window.open('http://yoursite.com/script.pl?workorder=yes&cust
+omer=0876','mywindow','width=400,height=200')"
[download]

You can pass information to your script using valu pairs in the url like above. As far as I am aware, there is no server side way to do this, you have to use a client side scripting technology such as javascript. You can get more information on that javascript here if you are interested.
Regards, Gerard