How to get the current login user name in my Script file inside my asp.net mvc

You will have to set a javascript variable in your view (.cshtml) using razor and then use this in your script file (.js)

So in your view:

<script type="text/javascript">    
            var userName = '@HttpContext.Current.User.Identity.Name';            
</script>

and then your script file

   var fullurl = '....loginAs=' + userName  + 'packageId=' + name;

$(document).ready(function () {
    var name = prompt("Please enter your packageid", "test");

    var fullurl = 'http://localhost:8080/jw/web/json/workflow/process/list?j_username=kermit&hash=9449B5ABCFA9AFDA36B801351ED3DF66&loginAs=' + <%= HttpContext.Current.User.Identity.Name %> + 'packageId=' + name;
    $.ajax({
        type: "GET",
        url: fullurl,
        dataType: "JSONP",
        success: function (result) {

the above code should work, on the javascript front you will not have access to HTTPContent object which is available only on the server, but putting them in a server code you should be able to access the same.

or you can have a hidden control with the value set from the server

<input type='hidden' id='uid' runat='server'>

server code would look like

uid.value = HTTPContext.Current.User.Identity.Name;

Your script is looking for a Javascript variable called HttpContext Your code should be

@HttpContext.Current.User.Identity.Name

in Razor

so the javascript becomes

 var fullurl = 'http://localhost:8080/jw/web/json/workflow/process/list?j_username=kermit&hash=9449B5ABCFA9AFDA36B801351ED3DF66&[email protected]&packageId=' + name;

You're also missing and & between the user name and packageId if you intended for them to be separate variables

Edit: based on your comment and this being inside of a js file (which I guess I missed in the OP)

Two options:

1. Is to hold the username inside a variable on the page calling the script file. Like this:

Page

<script>
var usrName = "@HttpContext.Current.User.Identity.Name";
</script>

JS file

....&loginAs='+ usrName + '&packageId=' + name;

Option Two is to not include the username at all and just get it from the Action. This is only an option if the page you're posting to is on the same app

You can use just User.Identity.Name that's derived from System.Web.WebPages.WebPageRenderingBase (that means the code should be in a View-file). You can't access server-side code directly in script-files.

 $(document).ready(function () {
        var name = prompt("Please enter your packageid", "test");

        var fullurl = 'http://localhost:8080/jw/web/json/workflow/process/list?j_username=kermit&hash=9449B5ABCFA9AFDA36B801351ED3DF66&[email protected]&packageId=' + name;
        $.ajax({
            type: "GET",
            url: fullurl,
            dataType: "JSONP",
            success: function (result) {
//code goes here