Failed to convert parameter value from a String to a Int32 c# - string

Question

I have two DROP DOWN LISTs :one for PROVINCE and one for CITY which are connected to a DB.
I want to be able to select a PROVINCE from the first drop down list and be able to see the
CITIES of that special PROVINCE in the second drop down list.
But I receive the error "Failed to convert parameter value from a String to a Int32." on line "DataSet ds1 = new DataSet();".
My DB:
--------
_Province
Prv_Id --- int (P.key)
Prv_Name --- nvarchar
--------------
_City
Cty_Id --- int (P.key)
Cty_Name --- nvarchar
Cty_Prv_Id --- int (F.key)
----------------------------
----------------------------
My ST.Procedures:
-----------------------
ALTER PROCEDURE [dbo].[_City_selectItems] (#vari int)
AS
BEGIN
SELECT * FROM _City WHERE (Cty_Prv_Id=#vari)
END
--------------------------------------------------
ALTER PROCEDURE [dbo].[_Province_selectAll]
AS
BEGIN
SELECT * FROM _Province
END
--------------------------------------------------
MY CODE:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
using System.Data.SqlClient;
namespace WebApplication3_DrpDwnListAndSQL
{
public partial class WebForm2 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
func1();
func2();
//func3();
}
}
protected void DrpDwnProvince_SelectedIndexChanged(object sender, EventArgs e)
{
Label1.Text =DrpDwnProvince.SelectedValue;
//string a = DrpDwnProvince.SelectedValue;
}
//First function for Province DrpDwnList
private void func1()
{
SqlConnection con = new SqlConnection("Integrated Security=SSPI;Persist Security Info=False;Initial Catalog=DrpBoxDB;Data Source=ARASH-PC");
SqlDataAdapter com = new SqlDataAdapter("_Province_selectAll", con);
com.SelectCommand.CommandType = CommandType.StoredProcedure;
DataSet ds = new DataSet();
if (com != null)
{ com.Fill(ds); }
DrpDwnProvince.DataSource = ds;
DrpDwnProvince.DataTextField = "Prv_Name";
DrpDwnProvince.DataValueField = "Prv_Id";
DrpDwnProvince.DataBind();
}
//Second function for City DrpDwnList
private void func2()
{
SqlConnection con = new SqlConnection("Integrated Security=SSPI;Persist Security Info=False;Initial Catalog=DrpBoxDB;Data Source=ARASH-PC");
SqlDataAdapter com1 = new SqlDataAdapter("_City_selectItems", con);
com1.SelectCommand.Parameters.Add("#vari",SqlDbType.Int).Value=Label1.Text;
com1.SelectCommand.CommandType = CommandType.StoredProcedure;
DataSet ds1 = new DataSet();
if (com1 != null)
{ com1.Fill(ds1); }
DrpDwnCity.DataSource = ds1;
DrpDwnCity.DataTextField = "Cty_Name";
DrpDwnCity.DataValueField = "Cty_Id";
DrpDwnCity.DataBind();
}
//Third function for District DrpDwnList
// private void func3()
// {
// }
}
}