Create Entity using Web API in Dynamics 365

Creating an account record with name "sample account" using web api's

https://msdn.microsoft.com/en-us/library/gg328090.aspx

// Request 

POST [Organization URI]/api/data/v8.2/accounts HTTP/1.1
Content-Type: application/json; charset=utf-8
OData-MaxVersion: 4.0
OData-Version: 4.0
Accept: application/json
{
    "name": "Sample Account",  
}

// Response

HTTP/1.1 204 No Content
OData-Version: 4.0
OData-EntityId: [Organization URI]/api/data/v8.2/accounts(GUID)

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function createEntity() {
    var entityName = "accounts";// Entity Name
    var clientURL = Xrm.Page.context.getClientUrl();// To get CRM client URl 
    var req = new XMLHttpRequest(); //Creating New HTTP request

    req.open("POST", encodeURI(clientURL + "/api/data/v8.2/" + entityName, true));
    req.setRequestHeader("Accept", "application/json");
    req.setRequestHeader("Content-Type", "application/json; charset=utf-8");
    req.setRequestHeader("OData-MaxVersion", "4.0");
    req.setRequestHeader("OData-Version", "4.0");

    req.onreadystatechange = function () {
        if (this.readyState == 4 /* complete */) {
            req.onreadystatechange = null;
            if (this.status == 204) {/* Status 204 denotes success */
                alert("account created from api");
            }
            else {
                var error = JSON.parse(this.response).error;
                alert(error.message);
            }
        }
    };

    req.send(JSON.stringify(// json object to be created
        {
            name: "sample account"
        }));

}