NSString *usernameString = usernameTxt.text;
        NSString *passwordString = passwordTxt.text;
        NSString *Grant_type = @"password";
        NSString *Finalstr = [NSString stringWithFormat: @"%@UserName%@Password%@grant_type", usernameString,passwordString,Grant_type];

 NSString * finalString = @"UserName=10122951&Password=123456&grant_type=password";

[post5 postServieCalling:@"%@myURl here" : finalString];

[post5 postServieCalling:@"%@myURl here" : Finalstr];