Trigger JavaScript With Button

Howdy,

I'm wondering how to trigger this script with a link/button?

I've placed the javascript below in the theme's custom JavaScript box.

Site: http://m24.siteground.biz/~websi541/toddsmithrmt.com/

Javascript added:

function launchWS(b){myHeight=screen.height*.8;myWidth=784;if(myHeight700)myHeight=700;var c=screen.height,e=screen.width,a=e/2-myWidth/2,d=c/2-myHeight/2-40;msgWindow=window.open(b,”ws_window”,”toolbar=no,location=no,directories=no,resizable=yes,menubar=no,scrollbars=no,status=yes,width=”+myWidth+”,height=”+myHeight+”, left=”+a+”,top=”+d);setTimeout(“msgWindow.focus()”,1)}

Thanks in advance,
Casper