// JavaScript Document
<!--
loc="home.html" // default page to load into Iframe
var str = location.search;
if(str != ""){
loc=str.substring(1, str.length)
}

function load_frame(){
document.getElementById('mainContent').src=loc // change iframe_id to the ID of your Iframe
}

// add onload="load_frame()" to the opening BODY tag

// -->