help needed Getting error while using Rest Client to make SFDC OAuth user password call

Hi,

I am trying to make SFDC Oauth Username password rest api call to get session key, however I keep get error message "error making http request: Bad Request".

I configured the domain name in Admin-> System->HTTP Client as  ".salesforce.com"

and created the following end point:

---endpoint code starts -----------------

<#assign url = "https://login.salesforce.com/services/oauth2/token" />
<#assign response = http.client.request("https", "login.salesforce.com", "/services/oauth2/token").body("{ 'grant_type':'password', 'client_id':'parameter', 'client_secret':'parameter', 'username':'parameter', 'password':'parameter' }", "application/x-www-form-urlencoded").post() />
<response>
<#if response.hasError>
<error>${response.error.message}</error>
<error>${response}</error>
<error>${response.error}</error>
<error>${response.status}</error>
<#else>
<content>${response.content}</content>
</#if>
</response>

---endpoint code ends ---------------------------------

I get below response to endpoint:

-------endpoint response start ------------------------

<response>
<error>error making http request: Bad Request</error>
<error>lithium.coreapi.webui.template.models.HttpClientResponseTemplateModel@4a048f3b</error>
<error>lithium.coreapi.webui.template.models.HttpClientResponseTemplateModel$Error@71579073</error>
</response>

-------endpoint response ends -------------------------

The same call works for me in advanced chrome rest client.

Can some one help with issue.

Thanks,
Sachin