Retrieving Entity Object Type code

// Retrieving Entity Object Type code based on entity schema name

function getObjectTypeCode(entityName) {
 
 try {

        var lookupService = new RemoteCommand("LookupService", "RetrieveTypeCode");
        lookupService.SetParameter("entityName", entityName);
        var result = lookupService.Execute();

        if (result.Success && typeof result.ReturnValue == "number") {
            return result.ReturnValue;
        } else {
            return null;
        }
    }
    catch (ex) {
        throw ex;
    }
}