Parameter Error in Stored Procedure

Question

Error:

 

Procedure or function 'SaveUpdateEmp' expects parameter '@EmpID', which was not supplied.

 

Stored Procedure:

CREATE PROCEDURE [dbo].[SaveUpdateEmp]
@EmpID varchar(10),
@EmpName varchar(100),
@DesID int,
@Salary money,
@Result varchar(50) out
AS
begin
declare @ID varchar(10)
select @ID= EmpID from Emp where EmpName=@EmpName
if(@ID<>'' and @EmpID='')
begin
set @Result='Employee name is already exist !!!'
end
else
begin
if(@EmpID='')
begin
insert into Emp(EmpName,DesID,Salary) values(@EmpName,@DesID,@Salary)
set @Result='Employee saved successfully'
end
else
begin
update Emp set EmpName=@EmpName,DesID=@DesID,Salary=@Salary where EmpID=@EmpID
set @Result='Employee updated successfully'
end
end
end

protected void btnSave_Click(object sender, EventArgs e)
{
try
{
SqlConnection con = new SqlConnection(Commons.GetConnectionString);
SqlCommand cmd = new SqlCommand("SaveUpdateEmp", con);
cmd.Parameters.AddWithValue("@EmpID", HiddenField1.Value);
cmd.Parameters.AddWithValue("@EmpName", txtEmpName.Text);
cmd.Parameters.AddWithValue("@DesID", ddlDesignation.SelectedValue);
cmd.Parameters.AddWithValue("@Salary", txtSalary.Text);
cmd.Parameters.Add("@Result", SqlDbType.VarChar,30);
cmd.Parameters["@Result"].Direction = ParameterDirection.Output;
con.Open();
cmd.ExecuteNonQuery();
con.Close();
lblMsg.Text = cmd.Parameters["@Result"].Value.ToString();
}
catch (Exception ex)
{
throw ex;
}
}