How to get the user name of thr crm 2011?

Question

how to Write the javascript function for getting the username(not a owner) in crm 2011.

Answer 1

If you mean the FullName attribute of a SystemUser record you can use this function:

function getCurrentUserFullName() {
    var serverUrl;
    if (Xrm.Page.context.getClientUrl !== undefined) {
        serverUrl = Xrm.Page.context.getClientUrl();
    } else {
        serverUrl = Xrm.Page.context.getServerUrl();
    }
    var ODataPath = serverUrl + "/XRMServices/2011/OrganizationData.svc"; 
    var userRequest = new XMLHttpRequest(); 
    userRequest.open("GET", ODataPath + "/SystemUserSet(guid'" + Xrm.Page.context.getUserId() + "')", false); 
    userRequest.setRequestHeader("Accept", "application/json"); 
    userRequest.setRequestHeader("Content-Type", "application/json; charset=utf-8"); 
    userRequest.send();
    if (userRequest.status === 200) {
        var retrievedUser = JSON.parse(userRequest.responseText).d; 
        var userFullName = retrievedUser.FullName;
        return userFullName;
    }
    else {
        return "error";
    }
}

reference: CRM Answers - Get current user's full name with a synchronous call

Answer 2

Xrm.Page.context.getUserId(); 

This returns the GUID of the current user.
Query the User entity with the retrieved GUID to retrieve the name and any other details associated with the user.