How to execute workflow through javascript in CRM 2013

Question

Hi,
I have created a business process and I want to execute workflow on custom button through javascript. I tried this script but this script does not run after message box show. Please tell me how to execute my workflow through javascript
function RunWorkflow() {
    var _return = window.confirm('Are you want to execute workflow.');
    if (_return) {
        var url = Xrm.Page.context.getServerUrl();
        var entityId = Xrm.Page.data.entity.getId();
        var workflowId = '541B45C9-3F88-4448-9690-2D4A365C3172';
        var OrgServicePath = "/XRMServices/2011/Organization.svc/web";
        url = url + OrgServicePath;
        var request;
        request = "<s:Envelope xmlns:s=\"http://schemas.xmlsoap.org/soap/envelope/\">" +
                      "<s:Body>" +
                        "<Execute xmlns=\"http://schemas.microsoft.com/xrm/2011/Contracts/Services\" xmlns:i=\"http://www.w3.org/2001/XMLSchema-instance\">"
+
                          "<request i:type=\"b:ExecuteWorkflowRequest\" xmlns:a=\"http://schemas.microsoft.com/xrm/2011/Contracts\"
xmlns:b=\"http://schemas.microsoft.com/crm/2011/Contracts\">" +
                            "<a:Parameters xmlns:c=\"http://schemas.datacontract.org/2004/07/System.Collections.Generic\">"
+
                              "<a:KeyValuePairOfstringanyType>" +
                                "<c:key>EntityId</c:key>" +
                                "<c:value i:type=\"d:guid\" xmlns:d=\"http://schemas.microsoft.com/2003/10/Serialization/\">"
+ entityId + "</c:value>" +
                              "</a:KeyValuePairOfstringanyType>" +
                              "<a:KeyValuePairOfstringanyType>" +
                                "<c:key>WorkflowId</c:key>" +
                                "<c:value i:type=\"d:guid\" xmlns:d=\"http://schemas.microsoft.com/2003/10/Serialization/\">"
+ workflowId + "</c:value>" +
                              "</a:KeyValuePairOfstringanyType>" +
                            "</a:Parameters>" +
                            "<a:RequestId i:nil=\"true\" />" +
                            "<a:RequestName>ExecuteWorkflow</a:RequestName>" +
                          "</request>" +
                        "</Execute>" +
                      "</s:Body>" +
                    "</s:Envelope>";
        var req = new XMLHttpRequest();
        req.open("POST", url, true)
        // Responses will return XML. It isn't possible to return JSON.
        req.setRequestHeader("Accept", "application/xml, text/xml, */*");
        req.setRequestHeader("Content-Type", "text/xml; charset=utf-8");
        req.setRequestHeader("SOAPAction", "http://schemas.microsoft.com/xrm/2011/Contracts/Services/IOrganizationService/Execute");
        req.onreadystatechange = function () { assignResponse(req); };
        req.send(request);
function assignResponse(req) {
    if (req.readyState == 4) {
        if (req.status == 200) {
            alert('successfully executed the workflow');

Answer 1

Hi,
I used this script for execute the workflow but its not working. When I used alert(req.status); then 500 show. Please tell me what did I mistake in my script.
function RunWorkflow() {
    var _return = window.confirm('Are you want to execute workflow.');
    if (_return) {
        var url = Xrm.Page.context.getClientUrl();
        var entityId = Xrm.Page.data.entity.getId();
        var workflowId = '541B45C9-3F88-4448-9690-2D4A365C3172';
        var OrgServicePath = "/XRMServices/2011/Organization.svc/web";
        url = url + OrgServicePath;
        var request;
        request = "<s:Envelope xmlns:s=\"http://schemas.xmlsoap.org/soap/envelope/\">" +
                      "<s:Body>" +
                        "<Execute xmlns=\"http://schemas.microsoft.com/xrm/2011/Contracts/Services\" xmlns:i=\"http://www.w3.org/2001/XMLSchema-instance\">"
+
                          "<request i:type=\"b:ExecuteWorkflowRequest\" xmlns:a=\"http://schemas.microsoft.com/xrm/2011/Contracts\"
xmlns:b=\"http://schemas.microsoft.com/crm/2011/Contracts\">" +
                            "<a:Parameters xmlns:c=\"http://schemas.datacontract.org/2004/07/System.Collections.Generic\">"
+
                              "<a:KeyValuePairOfstringanyType>" +
                                "<c:key>EntityId</c:key>" +
                                "<c:value i:type=\"d:guid\" xmlns:d=\"http://schemas.microsoft.com/2003/10/Serialization/\">"
+ entityId + "</c:value>" +
                              "</a:KeyValuePairOfstringanyType>" +
                              "<a:KeyValuePairOfstringanyType>" +
                                "<c:key>WorkflowId</c:key>" +
                                "<c:value i:type=\"d:guid\" xmlns:d=\"http://schemas.microsoft.com/2003/10/Serialization/\">"
+ workflowId + "</c:value>" +
                              "</a:KeyValuePairOfstringanyType>" +
                            "</a:Parameters>" +
                            "<a:RequestId i:nil=\"true\" />" +
                            "<a:RequestName>ExecuteWorkflow</a:RequestName>" +
                          "</request>" +
                        "</Execute>" +
                      "</s:Body>" +
                    "</s:Envelope>";
        var req = new XMLHttpRequest();
        req.open("POST", url, true)
        // Responses will return XML. It isn't possible to return JSON.
        req.setRequestHeader("Accept", "application/xml, text/xml, */*");
        req.setRequestHeader("Content-Type", "text/xml; charset=utf-8");
        req.setRequestHeader("SOAPAction", "http://schemas.microsoft.com/xrm/2011/Contracts/Services/IOrganizationService/Execute");
        req.onreadystatechange = function () { assignResponse(req); };
        req.send(request);
function assignResponse(req) {
    if (req.readyState == 4) {
alert(req.status);
        if (req.status == 200) {
            alert('successfully executed the workflow');