You can put this inside a script tag in the header.

document.onclick = function() { setupZoom(); }

or put an ID on your body tag and put:

document.getElementById("bodyid").onclick =...

If you still need it, this will delete all rows from your table, except for your head row.
var table = document.getElementById("tableid");
//or use : var table = document.all.tableid;

for(var i...