We have a script that basically pulls in, through use of API, Participation Type ID's, presents the user with the options, the user selects and the page refreshes and includes the variable "participation_type=XXXX" into the URL to allow the user to continue registration. IE is refreshing the page and does everything correctly up to the point of actually filling in the X's above with the correct ID. This works OK in Firefox, Chrome and Safari. Just not IE. I am placing the section of the code in it's entirety below But I believe the problem lies somewhere in the range of lines 120-130. Any help would be GREATLY appreciated! Thank you in advance!

Code:
var api = new ConvioApiClient('id', 'api_client.html', 'json');
var participation_id = null;
var fr_id = null;
var cons_id = null;
var sso_auth_code = null;
var team_search_results_rows = 0;
var team_id = null;
var team_name = null;
var event_name = null;
var participation_name = null;
var activeDiv = null;
var new_constituent = false;
var is_captain = false;
var fee = 0;
var additional_gift = 0;
var event_has_questions = true;
var event_requires_promo_code = false;
var event_supports_upsells = false;
var event_supports_secondary_registration = false;
var user_can_select_team = true;
var user_can_select_company = true;
var user_can_select_team_division = true;
var user_can_create_team_password = true;
var user_must_accept_waiver = true;
var event_has_discounts = true;
var process_registration_request = '';
var populate_team_pages_called = false;

function toggleDiv(hideDiv, showDiv) {
    if (hideDiv !== null) {
        document.getElementById(hideDiv).setAttribute('style', 'display:none;');
    }
    if (showDiv !== null) {
        document.getElementById(showDiv).setAttribute('style', 'display:block;');
    }
    activeDiv = showDiv;
    return;
}

function getParm(name) {
    var regexS = "[\\?&]" + name + "=([^&#]*)";
    var regex = new RegExp(regexS);

    var results = regex.exec(window.location.search);
    if (results == null) {
        return "";
    }
    return results[1];
}

$(function () {

    $(document).ready(function () {
        activeDiv = 'search_for_team_div';
        fr_id = getParm('fr_id');
        participation_id = getParm('participation_id');

        if (fr_id == "") {
            window.location = 'find_event.html';
        }

        parms = {
            fr_id: fr_id,
            participation_id: participation_id
        };

        if (parms.fr_id != null) {
            api.callTeamraiserAPI("getParticipationTypes", function (response, status) {
                console.log('getParticipationTypes:', status);
                console.log(response);

                //find participation type
                var i = 0;
                var r = null;
                var types = jQuery.makeArray(response.getParticipationTypesResponse.participationType);
                var activeCount = 0;
                var activeIndex = 0;
                for (i = 0; i < types.length; i++) {
                    if (types[i].id == participation_id) {
                        //found the participation type passed in, grab it and bust out
                        r = types[i];
                        activeCount = 1;
                        break;
                    }

                    if (types[i].active == 'true') {
                        //set up particpation type selector
                        var dlg = document.getElementById('participation_type_dialog');
                        var elem = document.createElement('input');
                        activeCount++;
                        activeIndex = i;
                        elem.type = 'checkbox';
                        elem.id = 'part_index_' + i;
                        elem.setAttribute('onClick', 'participation_id=' + types[i].id + ';');
                        dlg.appendChild(elem);
                        elem = document.createElement('label');
                        elem.setAttribute('for', 'part_index_' + i);
                        elem.innerHTML = types[i].name;
                        dlg.appendChild(elem);
                        elem = document.createElement('p');
                        elem.innerHTML = types[i].description;
                        dlg.appendChild(elem);
                    }
                }

                if (r == null) {
                    if (activeCount < 2) {
                        //there was only one active participation type, so use it
                        r = types[activeIndex];
                        participation_id = r.id;
                        parseParticipationType(r);
                    } else {
                        //display the participation type selector dialog
                        $("#participation_type_dialog").dialog({
                            modal: true,
                            width: 600,
                            buttons: [{
                                text: "OK",
                                click: function () {
                                    window.location = 'registration.html?fr_id=' + fr_id + '&participation_id=' + participation_id;
                                }
                            }]
                        });
                    }
                } else {
                    parseParticipationType(r);
                }

                return false;
            }, parms);
        }
        return;
    });