eswar.aspire,
First off, you need to post your questions in the correct forum. This is purely Javascript not PHP, because your asking a question that has no PHP in it.
Secondly, what you need to have in your parent page is a function that will control the iframe sources.
function load_left(url) {
document.getElementById("menu").src = url;
}
In the "login_reg" page that gets loaded in the "page_load" iframe, you need to impliment this with the jquery, so when you click submit it calles the function on the parent frame and loades the "menu" iframe with the desired page.
$("#login_form").submit(function() {
parent.load_left('../pub@lic_profile/@_profile/all_@_all/horizontal_menu/flashmo_114_horizontal_03.swf');
});