Change Onload File to Onclick File

[linklobby.com]

Hello all, I am new here and have a question about a AP Div I am using as a dropin. It drops in when the page loads and I would like it to only drop in if a visitor clicks a link I designate as the dropin link. Can someone please tell me how to accomplish this? I am pasting in the js file and I will also need to know how to set up the "a href" link to call the dropin! Thanks is advance for any help you may give!

// JavaScript Document

var ie=document.all
var dom=document.getElementById
var ns4=document.layers
var calunits=document.layers? "" : "px"

var bouncelimit=32 //(must be divisible by 8)
var direction="up"

function initbox(){
if (!dom&&!ie&&!ns4)
return
crossobj=(dom)?document.getElementById("dropin").style : ie? document.all.dropin : document.dropin
scroll_top=(ie)? truebody().scrollTop : window.pageYOffset
crossobj.top=scroll_top-250+calunits
crossobj.visibility=(dom||ie)? "visible" : "show"
dropstart=setInterval("dropin()",50)
}

function dropin(){
scroll_top=(ie)? truebody().scrollTop : window.pageYOffset
if (parseInt(crossobj.top)<100+scroll_top)
crossobj.top=parseInt(crossobj.top)+40+calunits
else{
clearInterval(dropstart)
bouncestart=setInterval("bouncein()",50)
}
}

function bouncein(){
crossobj.top=parseInt(crossobj.top)-bouncelimit+calunits
if (bouncelimit<0)
bouncelimit+=8
bouncelimit=bouncelimit*-1
if (bouncelimit==0){
clearInterval(bouncestart)
}
}

function dismissbox(){
if (window.bouncestart) clearInterval(bouncestart)
crossobj.visibility="hidden"
}

function truebody(){
return (document.compatMode && document.compatMode!="BackCompat")? document.documentElement : document.body
}


window.onload=window.setTimeout(initbox,5000);