Get string by integer - sql

Question

I have a column in db stores Entityid and other one stores Entityname , i need a stored procedure that get name when user insert id (by column name), i have one am working on, how can i improve it.plz explain..
ALTER procedure [dbo].[Emp_CompanyHirarchy]
#FK_CompanyId varchar(50),
#FK_EntityId varchar(50)
AS
SELECT * FROM dbo.RetrieveEntityParent
WHERE (EntityId =#FK_EntityId)
when i excute this, error keeps raise:Msg 216, Level 16, State 1, Procedure Emp_CompanyHirarchy, Line 5
Parameters were not supplied for the function 'dbo.RetrieveEntityParent'.
the function dbo.RetrieveEntityParent:
ALTER FUNCTION [dbo].[RetrieveEntityParent] (#FK_EntityId int)
RETURNS TABLE
AS RETURN
with p as
(SELECT EntityId, FK_ParentId , EntityName ,EntityArabicName
FROM OrgEntity
WHERE OrgEntity.EntityId=#FK_EntityId
UNION ALL
SELECT PA.EntityId, PA.FK_ParentId, PA.EntityName,PA.EntityArabicName
FROM OrgEntity as PA
inner join p
ON p.FK_ParentId = PA.EntityId)
select * from p

Answer 1

There is an example for your need in this link , but there is a simpler way using the parameter directly in this link .
DECLARE #FK_EntityId INT
SET #FK_EntityId = 1
SELECT EntityId, FK_ParentId , EntityName ,EntityArabicName
FROM OrgEntity
WHERE OrgEntity.EntityId = #FK_EntityId
UNION ALL
SELECT EntityId, FK_ParentId , EntityName ,EntityArabicName
FROM OrgEntity
WHERE FK_ParentId = #FK_EntityId

Answer 2

I can't find Employee referred by Employee.FK_EntityId in your RetrieveEntityParent.
Do you mean OrgEntity.FK_EntityId
after your Edit, to get Emp_CompanyHirarchy work you would have to transfer #FK_EntityId as parameter
ALTER procedure [dbo].[Emp_CompanyHirarchy]
#FK_CompanyId varchar(50),
#FK_EntityId varchar(50)
AS
SELECT * FROM dbo.RetrieveEntityParent(#FK_EntityId)
-- WHERE mybe some other condition
BTW: there is some parametertype missmatch with varchar and integer